Interesting post. I just got a Marconi 81 Tombstone from a man who inherited it from his grandfather. It is original unmolested unrestored condition, and has what appears to me to be the original knobs. FYI, while I love radio attic, great resource, I wanted to let you know the knobs on their Model 81 Marconi are probably not correct. I will take a Picture and post it so you can see what the correct knobs look like. They are all wood, even though, due to round shape they remind me of some of the plascon zenith knobs. Don’t know if this will work, but I attached the file.
73, Lee VA7TLE