I guess I should tell you guys the rest of the story. I was working on this gun at my kitchen table and had it dis-assembled and spread out all over the work area. I had just started a new relationship with my new girlfriend after a nasty divorce. She was watching patiently over my shoulder and was asking some very pertinent questions from time to time. I told her that I couldn't figure out why the maker of this gun had inletted a seperate piece into the wood under the lockplate. I had at first thought maybe it was supposed to be a support piece for the lockplate of some kind, but that didn't really make much sense. I had never had it out before and didn't know it was slotted. She got to messing around with it and managed to get ahold of it with her long fingernails and extracted it from the stock, that's when we found it was a spring clamp. She also noted that there were threads cut inside the holes in the hammers, that's when the light finally came on in my head and I tried the lockbolt in one of them and found out it was a fit.
I have used spring clamps for years on muzzleloading mainsprings so it wasn't much of a stretch to figure out how this one worked. All very compact and convenient, and it could be worked on out in the field if necessary, with just a screwdriver.
You may have noticed that this is an old gun, on the barrels there is a loading inscription on both side that states "2G Sch.P. 27g Bl." I think this refers to 2grams of Schultz semi-smokeless powder OR 27 Grains of Black powder, in other words, this was made during the period when they were in the process of changing over from black to semi-smokeless powders and they didn't want anyone to get confused about the proper loading of this gun!
I decided after this experience that Marie was a keeper and we later got married. She has helped me many times to figure things out or to offer and extra hand when needed during the disassembly or re-assembly of guns. She was raised in Holland and knows German as well as a couple of other languages and that has come in handy more than once. We have now been together over 11 years and she still surprises me once in awhile. She just told me that "Verschluss" means "lock" in German, so "Nimrod Verschluss" means "Nimrod Lock". She also keeps track of my appointments, and my meds, and also takes these pictures for me, (I am not a good photographer). I think I'll keep her awhile,yet. Bob H.