Breaking out the "C" box and going straight for one of my favorites. Consolidated Mines & Metals operated in San Francisco in the 70's and 80's. The outstanding attention to detail and additional time taken in production that resulted in the polished shape and mirror-like finish on these examples is truly unique.
The first ingot pictured includes the Certificate of Authenticity dated November 5, 1980. Couldn't decide if I should show the obverse of the ingot or reverse with serial number but I swear, it is a match!
The second picture represents the two types I have come across to date. The example on the left matches the 1980 obverse above. The one on the right matches a listing Tom has of three in sequence dated 1981. That would indicate the type on the left is the earlier but with only two certified examples, more research is needed to say for sure.
Most recently a number of listings have appeared of examples without serial numbers, always thought to be more rare than those with serial numbers.
Much more from the "C" box to follow.