1st mould is Ideal-marked, #454190 single-cavity. Meplat is .210".

2nd mould is Lyman-marked, #454190, double cavity. Meplat is identical, and castings from either weigh right at 252 grains in 92/6/2 and mic #.455"-.4555". I cannot see a difference between the cavities of both moulds.

FWIW, I have a similar pair of #454424s, and they they DEFINITELY differ. Markedly. Lyman's adherence to design standards is somewhat poetic, it seems.

ALL of these castings have a short, "squatty" aspect to them not presented well in catalog sketches.