When I look at the responses here, and then look back at your question, and then look again at the responses... I'm not sure if you're sure what you wanted, and whether you're getting what you asked for. Some very good suggestions here already, but quite a few of the players mentioned are anything but "rare" in terms of having considerable fame, and numerous recordings (some on major labels). I'm also not sure how "straight" you prefer your "straight ahead". At any rate, it's all good, I'm just not sure how much you've already heard, or what exactly you're looking for. The actual "rare" ones are kind of pointless to recommened, because... well, they're rare. You're not going to find them, most likely.
I'll add these names, all highly recommended:
Louis Stewart
Ron Eschete'
Joshua Breakstone
Mark Elf
Reg Schwager
I don't mind the criteria being stretched a little. I've heard the work of the most famous jazz guitarists, but I have very spotty exposure to the rest of the field. I like it pretty strait ahead as opposed to fused with non-jazz genres. Rare stuff that I would have to work a little to find is good - I like the hunt. But you're right - if it's super-rare, such suggustions would just be a tease. Thanks to all who have replied and all who will!