For those interested in the roots of ska, rocksteady, and early Jamaican music in general, I highly recommend checking out Dub Store Records. The label is based out of a store in Tokyo, and has a website. I'm not sure if they're still operating, but many of their releases (besides the numerous 45 singles) came out on compact disc in the 2010's and are terrific. One compilation I recommend is Kentone Ska From Federal Records:
Another excellent "dub" instrumental record is Errol Brown's Orthodox Dub. (For Bauhaus fans—you'll hear where they got some of their inspiration.)
Anybody else here familiar with Dub Store? Their discs are fairly expensive and mostly out-of-print, but ImportCDs still carries a fair amount.