I think the term Skinhead reggae describes the music recorded in Jamaica (and the UK, eg Symarip, Pama Dice et.c) which was post rocksteady (with the fast organ and guitar licks, and different beats) but generally recorded pre 1971 (unless DJ voiceovers are included)....I suppose it is a similar generalisation to the term Northern Soul
It's a shame, as there so much good reggae the skinheads are missing out on (eg good heavy roots, and rockers), but presumably they are only allowed to dance a la moonstomp and must follow the rules at all times to fit in