You could try some Japanese importers, the Nissan March's were available with 1 litre engines with supercharging, maybe they are where these blowers come from. I think the engines were the MA9 & the MA10. Those wacky,zany guys stuck all sorts of things on their little engines, like turbos & blowers, sometimes at the same time. Small superchargers like that aren't in much demand, though,so they maybe hard to find. So let your fingers do the walking, as an old sponsor of Mark Webber used to say.