Another likely source for repro filters is listed as part WO-A-7850 at
http://www.debellajeepparts.com/mbgpwfuel.htm I don't guarantee that the assembly is identical but I found the spring that Peter DeBella sells for the jeep filter fits the CMP filter. (And this one is cheaper than the one above.)
I also recently snagged a filter from a gent who sells DUKW parts on ebay that is described as a DUKW filter but seems dimensionally similar to the CMP so CCKW is also probably similar