This amazingness is on eBay right now:
Ghana, West Africa – 1980s. Quasi-legal ‘mobile cinemas’ showed exploitation films on VHS around third-world villages, promoted by off-model movie posters painted by local artists. Luckily for the rest of the world, these miracles of advertising art survived and are circulating galleries, museums and collectors markets.
Check out a bunch here, here and here.
There’s a great book on these ultra-crude but endlessly fascinating hand-painted posters called Extreme Canvas, and martial arts exploitation films are well represented.