> get one made at a machine shop.
When I needed some metal parts fixed for the last project I worked on, I went to the local Technical College and spoke with the shop instructor. I made a $50 donation to the school and had all my welding work done par excellence! They have Machine shops in those schools! Tell the instructor you're working on a vintage drum with hard to replace parts. Show him what you need made. If you present it as a cool class project, they'll be happy to manufacture the parts for you so that the kids can get some real-world work experience. Win/win all around. I have to tell you, I had big fun hanging out in the shop watching the students work on my project. They really got into it and they did a superlative job for me. Consider it! There has to be a schematic for a four point strainer online somewhere. You can also bring the drum and show them photos of the missing/needed parts. They'll take it from there.
John