Hi Pete,

Caliber designation:
Normally you can find caliber designations and proof marks on the outside of the barrel near the chambers or under the frontend of the gun stock.

Reloading data:
If you send me a PM with intended bullet weighs and powders I can provide reloading info.
Also chamber dimensions, but my info is from the current data table of german proof law specifications, therefore dimensions can vary a bit to your gun, dated to 1905.

Components:
If you do not find components in USA (Huntington?), then I would recommend the german firm of Johannsen (www.johannsen-jagd.de). They have a nice catalogue (also in english language) for components for reloading many (rare) european cartridges (beware of the somentimes stiff prices).

Rolf