Elmer designed the 358431 as the hollow based version of the 358429, and the 358439 as the HP version. Later they called it the 3585429 HP, but I have one marked 359439.
There was a HB version of the 429421, too, I believe it was 429422. My bet is finding the mold would
be a difficult search.
Which one is that 358156?
Bill