I've worked over defective junk Lyman moulds six ways from Sunday. All of the alignment pins I've seen on the 2c blocks are domed and usually set about right from the factory. The only real problem with the moulds is the way they're bored, which is not square, not deep enough in the blocks (operator not clearing chips), worn out cherries, and worn out or mis-adjusted double-acting boring vise ways which allow the blocks to slide in opposite directions, causing misalignment of the cavity halves. The pins and outside dimensions of the blocks have been pretty near perfect on every new Lyman mould I've bought.
I have two 457124 moulds that are utter garbage. The newer one MIGHT make .455 on the fat side with 20:1 alloy. The older one has the cavities so misaligned that the pin holes would have to be re-drilled to fix it. I also have the 505 grain round nose bullet and that is a good mould AFTER I moved the alignment holes over over about 1/3 of their diameter by filing one side and peening the other. I'm SO done with Lyman's sorry junk. I even ordered a 311679 a couple years ago from Optics Planet (of all places!) hoping to break the jinx or escape the note on Lyman's mailroom wall that reads "send all our junk rejects to Ian", but to no avail, had to spend half a day lapping and fixing the alignment issues on it, too. It's nose was .301 x .297, body was .310x.306 because, once again, the cavities weren't cut to full depth in the block faces even though that cherry was in good shape.