I purchased a rolling block labeled as a E. Remington & Sons No. 1 Military Rolling Block Rifle here is the link for photos. I am trying to confirm the correct model after digging into the Layman Book.
t is marked with the E Remington & Sons Patent Dates last of 1874
35” Round Barrel
“H” Stamp on Receiver and Barrel
Cartouche stamp on stock inside a square is HBH, (H.B Hart Inspector)
Lug is the Long Lug marked on the bottom of the square portion of the lug with what looks similar to an “H” but not a US looking H, as it sort of has arched verticals on the Vertical lines of the H.
TANG Length are equal
Tangs are stamped on left side with 24044 on both upper and lower tangs.
The H.B.H cartouche is usually associated with the New York National Guard
rifles but yours doesn't appear to be of that type. The basic pattern matches
the "Spanish" model (which are usually in 43 Spanish caliber). If it is .43 Spanish,
you should be able to see the bottle neck step in the chamber.
If you have studied George Layman's book on military rolling blocks, you know
that the number on the tang are considered lot numbers and not serial numbers.
They were used to re-unite the two halves of the frame after they had been
polished and finished.
I have several Spanish models in my collection and the groove diameter of the
barrels can vary considerably. The ones I have run the gambit from .4395" to
.4425". This was considered normal because soft lead bullets would obturate
and fill the extra space.
Your frame is the type 4 with no step and rotary extractor which was the last
type of the #1 rolling block. It was replaced by the #5 frame when the rolling
block was manufactured in smokeless calibers.