ok, so this is probably something I should be familiar with, but I'm not.
What is this 1874 roller? weird thingy on the block, loaded chamber indicator? how about the barrel config and proof marks.

possibly a Danish sporter? (Husky?)  8mm?

Thanks, Aaron

(I ain't never seen one of them )

The "Crown over the C" mark indicates this was a M1867 Swedish Rolling Block in 10.15x62mmR originally manufactured in 1874 by Carl-Gustaf.

These rolling-block actions were eventually converted to the very modern centerfire cartridge, the 8×58mmR Danish Krag (bullet diameter .322 in/8.17mm, bullet weight 237 grains/15.29 grams, muzzle velocity 1,965 ft per second/600 m/s), with the designation "gevär m/1867-89" used for converted rifles.
The conversions to 8x58R were done from 1889 to 1896.

However with the development of the Swedish Mauser 96 these converted Rolling Blocks were sold as Swedish Sporters.

The conversion included installing new hammers and rolling block, case hardening the original action, shortening the forearm and installing a new 8x58R barrel. 
The old straight extractror screw hole was plugged and a lower screw was made to hold a new circular extractor. 
And yes the new rolling block had the firing pin indicator installed that you are asking about.

There will be a year date on the barrel which indicates when the conversion was done at the Carl-Gustaf factory.

Picture of a converted Swedish Sporter, a circular extractor, and the 8x58R cases made from .45-90 cases.

That is pretty much the normal price for the sale of these Rolling Blocks.

They are always in very excellent condition after the 8x58R conversion and should sell for more than the over used and abused Remington Rolling Blocks.

The 8x58R extractor is perfect size for a .45-70 or .40-65 barrel conversion.

I kept one original and converted a second one to .38-50 Remington Hepburn.
Picture attached.

I was told some years back by a gun collector in Sweden that these converted Rolling Blocks were transferred to "Foresters" their version of game wardens, or Forest Service workers. Then eventually went into storage and were sold as surplus to other countries, and civilians.
These are pretty nice variations or reworks, and as mentioned often too nice to tear apart to use for modern BPCR action builds. If they ever need parts it can be more difficult to find for certain parts are unique to this reworked action.