The combo moulds I've seen so far appear to date from the late 50s to early 60s. I suspect the buyer who ordered most of them was stretching their budget by ordering a single two cavity with two designs. Perhaps the most practical ones had one wadcutter cavity and one SWC, so one target bullet and one hunting bullet for versatility. My current version is a 358250 and 358156. Others I've seen were a 452488 target bullet & 452374 RN, plus others. This was also available for four cavity blocks as well, and the coolest one I've seen was all four .452 catalogue designs from Lyman in the early '60s. I really wanted this mould, but the seller was well known on that auction site for misrepresenting condition of his merchandise, and when he claimed that this mould just came back from Lyman after a factory overhaul I had seen and heard enough. I left it be, and it took a long time for him to sell, so I probably made a good decision.