I've just about finished cleaning the metal parts. Externally it is NRA good. The bore is shiney with some very minor roughness; really nice. Lock is absolutely crisp. I have yet to make a nipple wrench, and the flash channel is plugged, probably with grease, as the inside of the action was clogged with old hardened grease. With the breech closed, I blew hard into the muzzle, and there was NO escape of air at the breech.
green - I would imagine that the blue closing disc was intended to allow the cap flash to pass through. Interesting that the grease grooves are within the linen case. For hunting, cartridges would be nice. For target shooting, a bullet could be breechseated, and loose powder measured into the chamber.
dingus - the catch to trying to use a Spencer as a repeater with offset .22s for primers is that you cannot insure that the .22 head will come up under the firing pin. These cases work when single loaded. Spencers in good working order are not inexpensive.
No trace of inspector's or unit marks. No WD either. Just three intials of a previous owner.