Tons of aftermarket for them, they used to rally them in the good old days ie Paddy Hopkirk..... wouldn't be that hard to get 100 hp out of it. There is alot of very amusing and interesting stuff about those cars.. For instance, the early prototypes had the engine facing the other way, but they had to turn it around because it would get carb. icing, the next problem was the fact it had one forward gear and several reverse... LOL

very fun cars my dad has owned a couple..
I always fancy getting Mini Sprint(a chopped Mini) adding webber carbs and a Peco free flow exhaust, and other fun stuff....
Check out Mini Mania, you should find what you need....