My intuition tells me I run a chance of gumming up my bottom pour, but here's my lazy idea. Cut pewter into pre-weighed pieces, and throw directly into the mix when pot is up to temperature. Throw in a pinch of parrifin and a pinch of pine tar, stir, scoop, and call it good. I have done similar with Linotype and Monotype without any ill effects. Has anybody tried throwing pewter straight in the pot, or is smelting into ingots considered necessary?