On another cannabis site, word is that thousands of Panama Red seeds were found in storage, up in Alaska. Reputable breeder, (ReeferMan...same guy I got my PokerFace strain from years ago) so I'm wanting to believe the story, but marketing on emotions is a powerful tool. Panama Red disappeared decades ago, (in the late 70's...?) but he said he germed some out (low germ rates, but successful) selected the heartiest, with best Panama Red characteristics. I believe that by now he's selling them, but I haven't been back there in a while.

Personal experience, tho...I keep my seeds in a dark closet in a couple of those clear jar spice racks. 12 bottles on a wood-framed carrousel. I've germed seeds that are up to 8 years old, but I have none that are older, so can't really go beyond that. Keep 'em dry and dark...they last quite a while. Make sure the seeds are dry and free of leaf-litter. Mold can form quickly.

Most folks in here freak at the mere mention, but gibrellic acid can be used to force stubborn hard-shelled seeds to pop. I've used it a few of times on palm seeds and old cannabis seeds. (MegaGrow.com)

A light scuff along the seed suture with fine sandpaper often helps, too.