There's a lot of full race videos up on YT, but unfortunately for the good Mr. Edwards here of this parish they all appear to be of Oz origin and thus contain commentary by his most beloved compatriot, Mr. Sherry Bean 
Nevertheless, I always find it fascinating to watch full race clips instead of the usual highlight videos, and most of those I hadn't seen even in the day because Motorcycle racing in Germany got VERY little air time, and most (if not all) of it was limited to the lower classes where German riders had a chance to win - we were lucky to even only catch a glimpse of the 500cc action!!
Here's a video of the first ever 'modern' (IRTA) 500cc Grand Prix in 1992, incidentally also the first race (I think) for the Big Bang Honda, and what a phantastic race it was despite Doohan's clear cut win. Watch Champions fall (beginning with Mamola on the warm up lap!), and watch Gardner pick up again on a wreck of a bike to ride back into the top six, a superb performance which was sadly poorly rewarded.
