Hi Ross luckily I haven't had to get many parts. The tank and half the kick start I found through this forum. (thanks Macho Mick) I got a few Bits from OSSA world in the states and Mike Warner wheels made some spokes up for me.
We have a sand blaster at work it's had more use on my motorbikes than the any work gear. It's great especially for aluminium it comes out a bit rough then you hit it with a wire brush in the die grinder and it comes up 100% better than it was.
But as you Know finding part for parts for old Spanish bikes isn't the easiest. Alot of time on the internet