This helps a lot Ric, you're making my day! I originally thought I had mismarked blocks, then I couldn't find anything in print that matches my moulds profile. Doug Elliott gave me a bunch of research material on Ideal a couple of years ago, and none of this is in there either.
Persistence pays off occasionally. This mould was listed on GunBroker for a long time, but with the wrong picture in the auction. The pic shown was for a later 358429 so I asked the guy for the correct pic, and it took him ages to get it corrected. I was looking for a 452460 for a hollowpoint conversion. Finally the guy posted the correct pic and I bought it instantly knowing everything is out of sync with the blocks and profile. I cast a few samples today, and it now goes into the treasure box. I simply must buy more Ideal manual reprints.