Crown stamp on barrell bands

[figo]

Hello all,
I am looking for information on a no. 1 rolling block I have. Here is the information I have. Patent dates of Nov 15 1864 and April 17 1865. The muzzel measures .45 the breach, .52. There are 3 Barrel bands with a crown stamped on them. Serial number 52337 on the upper and lower tang. No markings I could find on the barrell, it does hava a bayonet lug.

Thanks for any help,
Frank

[tjack]

Frank, I'm going to guess that your rifle is the early export model (based on tang patent dates) and chambered for the 11mm Spanish (aka .43 Spanish) cartridge. The "Spanish" rolling blocks frequently have oversize bores (supposed to be .439") and the cartridge has a base diameter of about .516".
The Egyptian cartridge has a base diameter of about .581". The numbers on the sides of the tangs are assembly numbers. The large frame military rolling blocks generally had no serial nimber.