Turkish "B" action, buttstock, swivel, and buttplate.  Though Henry rifling is present, outside barrel contour is wrong, especially at the breech(reinforce missing).  Probably started life as a musket, barrel cut off at breech end, rechambered.  SN 510590 (see Peabody Military Rifles, Turkish for interpretation of the turkish numerals) 
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Current chambering is anybody's guess without a chamber cast.

Well that pictured carbine certainly doesn't have the chamber reinforce that is found on the rifles!.  OTOH, no provision for sling ring bar.  Since Providence was stuck with a couple hundred thousand unpaid Turkish arms, I suspect they found all kinds of uses for them.  I searched around on line  in vain for P-M carbine pics.  where did you source yours?

I have one of the Peabody turk rifles that never went there.  A pretty accurate rifle in deed, the 45 Turkish is a very good cartridge.  And the chamber is pretty tight too - so tight I need to neckturn my reformed 470 NE brass.

Well, it doesn't have any Turk acceptance marks, and the rear sight is graduated in 'normal' numerals.  For the rest, it is identical to a Turk 2nd model, including the Tugra.   
Loads?
Pretty easy , actually:  somewhere between 80-85grs of Fg or 1 1/2Fg, card overpowder wad and a 480-530gr .458 bullet seated in a necksized case (to get some necktension - I use a Lyman Postell), the bullet seated out about 2 Grease grooves, but not touching the rifling.
I shoot both converted Kynamco #2 Musket brass (yes, I know!) and federal .470 NE.
Shoots a treat, provided you can handle the rear sight.  I cannot, so I replaced it with a  somewhat more modern sight ladder (Brit Martini post Mk I).
Blowtubing between shots, 5-6 long, deep exhales.  Will easily keep the 9-ring on the ISSF 25m pistol target at 100m, and probably better too.  The rest is up to the shooter... (I only shoot prone, unsupported, with sling)
Every bit as accurate as my Roumanian Steyr in #2 Musket, maybe even better.

That's indeed the big issue for accurate shooting.  Mine's now in a little bag, just in case I need it later, and to keep the rifle complete.
Just preppped some Federal 470 NE brass, which is now duotone (Cases are nickeled, but the necks havebeen turned, so...), and they are loaded and ready for fireforming.  something for thursday or sunday.

John,

Just make sure you put that buttplate where it belongs, and pull it tightly into your shoulder so as not to give it a running start, and recoild will be surprisingly mild...  More us push than a kick, even though she will move quite a bit.  But it won't hurt.  OTOH, if you put that buttplate the wrong place, or don't pull the buttstock into your shoulder, she'll let you know for sure!

Those of you with Turkish Peabody-Martini's:  What marks do you find on the barrel at the breech under the fore-end?  Any signs of a serial number, witness mark for barrel threading, or other>  I have a musket that has a small letter "k", as does the carbine in question.  No other marks on these two.