Nice Hartford Sharps with what appears to be frontier use. Enjoy the rifle in it’s current state as you would degrade its value and historical significance if you were to make any changes to it. 
That Lawrence sight has a neat modification to full buckhorn. From the angle on the photo I could not even make a guess who’s did the work on it but it is certainly a plus to have it on your rifle.
The pewter forestock tip was typical of rifles made at the Hartford factory but it has nothing to do with a Hartford collar. The collar was an artifact of planing octagon barrels at that facility. The barrel on your rifle, having been re-barreled by Bergersen, does not have a Hartford collar. Please don’t take my observation to be detracting from your rifle. It's a special bit of American history just as it is.

That rear sight is interesting as it looks like it has had once or two pieces brazed on to beef up the buckhorn. Could we please get some additional pics ? Any other marks on the sight ? Have you contacted Dick Labowski to get a letter on the gun ? It is well worth the $. Does it have a standard front sight ? A lot of smiths during the period had sight modifications they would put on rifles coming out of their shops and they are distinctive. Freund Bros had the "More Light" Walter Cooper had his own style as well etc. The 40-90 cartridge seems to have been regionally popular and it was also a popular caliber with the Freund's. The tang break is really common and you need to get someone who is good at restoration work to look at it if you are going to have it fixed. Do not just take it to anyone. Even a "singleshot" gunsmith may not have experience making that repair. I can give you some names if you like. My bias is that the tangs tend to break there as the wood shrinks and the owner tightens down on the tang screws. If you have it fixed and keep cranking down on the tang screw it will break there again. The less you do to an old gun the better. Many old guns have been ruined with a heavy thumb and a little steel wool. The most fun of owning a gun like that is the history behind it. A letter from Dick and some additional research into Bergersen will increase your enjoyment of the gun and the value potentially. Best

z

This is the second P. Bergersen rifle in .40-90 I have seen.  I owned the other, it was a found item by me at an estate sale, and went to a collection in I believe Massachusetts when I sold it.  It was beat much worse than yours and had been cut off to 20 inches by a later owner to use as a ranch rifle/saddle gun.  Twenty years ago when these weren't worth nearly what they are today, mine, with a broken stock, bolts through the wrist, cut off barrel to 20 inches, buttstock spattered with blood stains, and forend worn nearly through from saddle horn wear sold for $1250.  It paid for John King to build my first target quality single shot, a rolling block .45-90 with a badger barrel and Axtell sights, which I still own and shoot today.  This was one of the best things I ever did in gun sales/trades, as it got me shooting single shots.  

Peder Bergersen was an immigrant, worked in the Chicago area, went to Cheyenne in the buffalo era, and I believe finished his career in Denver, maybe with Freund or Petersen?  I can't remember exactly.  

This is the real deal, a buffalo era rifle, tied to a frontier gunsmith heavily entrenched in the buffalo trade.  Nice piece of history.  I would do a tasteful repair of the tang, and age it to match the rest of the gun.  I would in no way do a refinish of the wood in any way, would do no polish or refinish of the metal.  Anything of that sort would drastically drop the value.  It's value is as a worn, authentic piece of 1870's American West history.  Any "restoration" detracts from that value.

If you are intent on having a shooter, I would sell this, as it is probably worth more than a new Shiloh Sharps, and purchase a new, easy to shoot caliber, accurate and guaranteed Shiloh.  That is what I did (sell original, build new target rifle), and I have absolutely no regrets about it.

dave

Nice rifle. Nice to see someone post an old original. I too have a rifle that looks like an old buffalo rifle. Old Remington RB 40-70 BN. Single set trigger, hunting sights on a heavy barrel. Then I get to thinking about it and remembering what I've read about buffalo hunting. Most old original Sharps buffalo guns were 50 - 45 caliber. I think the puny little .40 bullets just bounce off the old buffalo's. 
Maybe they're lady's buffalo rifles?     

        Joe.  

      

Dr Richard Labowskie 215-748-1376. Excellent resource on Sharps rifles. Has always been extremely gracious in helping to research a rifle. What he charges for a letter is nothing compared to the increase in value the letter provides. Even if the gun went to Dowagiac Michigan instead of Camp Supply it adds to the narrative of the gun and will increase its value.

Huvius,
I believe your rifle to be a general sporting/Hunting rifle. The calibre seems too small for a genuine Buffalo Gun which as Joe says were between .45 and .50 Calibre. Still it's an interesting rifle and worth while having minor faults being repaired.
Harry

When an archeological dig was done at the second battle of Adobe Walls (June, 1874), about ten years ago, cartridge cases were carefully catalogued.  Keeping in mind that almost all hunters reloaded their cases ten or more times and saved them except probably 50-70's, those recovered were 45-70 Van Choate, 45-70, 44-77 necked, 44-90 necked, and 50-2&1/2 (50-90, 50-110).  Rimfires ranged from 32L, through all Spencer types especially 44 Henry.  44 and 45 Colt centerfire pistol cases were also recovered.  40-70 and -90 were most likely used also, but none were recovered at this site.

J.Wright Mooar in his very factual record stated that he loaded 110 grains in his 2&1/2 inch cases.  This is the same caliber Billy Dixon used to knock an Indian off of his horse at what was later measured as 1028 yards the day after the main battle.  Didn't kill him but broke a rib according to the Indian account of the fight.

When my son got to help thin a herd when they had a dry year with no grass, I made him use one of my 45-70 original Sharps which took one shot.

James