Well......it seems a Fields Patent in 461 Gibbs #1 has found its way home.  I have brass...I have dies...not having much luck on .461ish bullets.  I believe the historically proper way to do this would be to paper patch...but I'm not down that rabbit hole.  Yet.  Anyone have good intel on a source for .461 bullets, 20:1ish??  I'm not super particular about bullet weight/design at this point....I just want to shoot it!  Something 500ish (I believe 540-570 was the 'original') would work....although a lighter bullet wouldn't hurt my feelings, nor my shoulder.     

Thanks!  Trails.....

Don't believe it's that rifle....this one is not engraved, but is in very good condition.  No clue as to the maker....but does appear to be a custom.

Curdog,

Depends - as target rifle cartridge, bullets usually were  500+ grains.  But is also was used as a hunting round, which had different bullets.
The reference load usually was marked under the barrel, assuming an original barrel.

The Field falling block is a very good action, 1 of my favourites.  It was used quite a bit by the guntrade - Field sold actions to whoever was interested.  And that includes several prestigious names.  The .461 Gibbs cartridge was a proprietary one, so in the day normally not used by other makers.  But if the barrel has been replaced, anything is possible.