I agree that the old maroon glass Polars are really useable and pretty bombproof. However, I've always preferred the Bear Cubs for a great low-cost longbow. The early honey-colored glass(made in '53 and '54, I think) one with straighter reflexed-limbs is better in my opinion, than the later black glass almost semi-recurve Cub. Cubs were made in weights up to 60#, so are not just for kids and ladies. I just picked up a 57 pounder for about $60 on the auction site, and it's a fine shooter.
I agree with Bjorn that the Pearson T/D recurves from the 50s were usually not great performers. I have a 61 pounder that is real decent, however.
Lots of other brands and makers, but only Hill and John Schulz longbows come to mind as classics from that era.
Some long time makers of customs certainly qualify, though the level of collector interest is questionable. Tim Meigs has been making bows forever, as Lon says Fred Anderson(not that he's so ancient, but he's been doing it forever!), Dan Quillian and others I can't think of right now. Cliff Coe made a bunch of bows for decades in Michigan and every state certainly has a number of similar old (local) bowyers from way back who made lots of longbows.
I shot longbows for decades, and loved them, but -for me, the reflex-deflex limb and today's hybrid custom bows have brought "longbows" to a new level of performance and shootability. The classic recurves were often comfortable, extremely fine performers - but, that's not something I'd say about those older longbows.