For anyone interested (I'm sure I'm not the only anal-retentive person out there who loves to know every little fact :-)) I just saw an auction on eBay for a Pig Pile by Judy Boyt and that is what the signature is on on the Pig Pile I have. I guess she re-released them through Borders Fine Arts. That's the only Pile piece I've found by them so far though. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=250260824472&ssPageName=STRK:MEWA:IT&ih=015
I don't think it looks as good as Martin's Version, it looks more translucent than opaque I think. But the bidding seems to be going well on it.