I loved this film immensely, and even recorded it from TV way back in the 1980's ... but sadly lost the film on a trip back to Africa. I could kick myself many times over.
For me, the attraction of the film was two-fold; primarily for the adventure, fun and humour, but also for the factual elements surrounding the sometimes profitable art of fossicking.
I doubt very much that it would every be released again, but I live in hope that the BBC or one of the Movie Channels will show it again (though usually of course, this happens at some obscure hour of the morning!)