I believe the X-Wing molds were the ones made by Grant from left over Pyro X-Wing castings. I have a set of these castings, the molds were pretty trashed when mine were poured in the 80's not sure what condition they'd be in now. I don't know the pedigree of the Tie molds but I believe they were all made in the 80's and are not original production molds or parts. Still, they'd be a nice thing to have...
http://www.icollector.com/STAR-WARS...S-AND-OR-MOLDS-MADE-BY-GRANT-MCCUNE_i28005609
http://www.icollector.com/STAR-WARS...S-AND-OR-MOLDS-MADE-BY-GRANT-MCCUNE_i28005610
http://www.icollector.com/STAR-WARS...S-AND-OR-MOLDS-MADE-BY-GRANT-MCCUNE_i28005609
http://www.icollector.com/STAR-WARS...S-AND-OR-MOLDS-MADE-BY-GRANT-MCCUNE_i28005610