Wow, fascinating stuff - the lens looks pretty modern... being an FD mount Canon, it can't date back morethan what - early-mid 70's?
The convex element is also something I have not seen before, but seems to make logical sense when you think about it...
Again, fascinating!

Now, I don't know if this is an urban legend or not, but there is a story in my family about a family member who worked as forced labour in a German instrument factory. She took ill and died, eventually, and the family was allowed to claim the body. In those days, the visitation was usually held in the persons home, the body lying "in state" usually in the biggest room of the house... All was well until during the night, the wind blew out the candles... The mourners were all of a sudden faced with a very..."luminescent" relative...

I have no idea how true that story is, but its a part of the family "folklore" if you will - I know the person was real, and that she died during the war, and was in fact taken to Germany as a forced albourer. That much is documented...the rest is very much word of mouth. The story goes on to include a lead coffin...and I guess it could be easily verified, but no one saw it as important enough to disturb the rest of the deceased (and most likely, rightfully so).