I have quite a few duplicate Texas Refinery Corporation and several hundred other promotional FDCs to trade for ones I need/want. For promotional FDCs I ONLY collect Texas Refinery Corporation, Ayerst ArtCraft and MARG covers. In all cases my preferences are addressed and with the original promotional letters and/or material still with the cover. Thanks
Have most of Artcraft after 1960 and maybe half 1950-1960. Also have pre 1950 cachet covers, including the first cachet by, I think, Fluiege Cover (?). Not positive which one that is, was just told by a FDC friend at my local stamp library it was a first one. Also have some Cachet Craft, C. Stephen Anderson and U.S. MAR.COM.PHOTOS (lol, early .com) pre 1950. Not sure if it matters but the pre-1950 are Scott #931 (pair), #932, #934 and #939.
Email me for pictures since I'm too lazy to resize images.
Edit: if I don't have what you need, I can prob get it cheap. I bought nearly every FDC from 1960-1980 for $0.02 each from my local stamp library. Can prob get almost anything you need. Just have to wait until they open.