On a different subject. I was able to get Mallory to build me two new YUL566AV distributors. I went through Jeggs Automotive and racing parts. Jeggs can be found on the internet at Jeggs.com.
I called Jeggs tech sales and asked about the distributors. They said they could have Mallory build them for me and they did. It only took two weeks to get to me. I haven't been able to put them in as of yet but they are identical to my YL566Av unilite conversion. The old ones mechanical advance was shot and hopefully these will work much better than the original with the conversion.
The point is; this could be a source for these distributors from Mallory. They even have the flat cap.