I've been cleaning today and again, I can't be more pleased on the condition of the rifles. All the barrels look fantastic, I was worried they might be destroyed from corrosive ammunition. So far so good. They are getting a deep cleaning and I am learning more about MKIIIs I've attached three pics of the rifles I've started to clean. The M10 had an odd proof mark. "Not English Make" I am assuming the RCA stamp on the wood - Royal Canadianicon Artillery?