Hi mate, I've just had a look through your project thread with regards to the Rota's.
These wheels are a real pain to fit!
The lad I bought my Rota Grid Drift's from had already had them lathed. I couldn't tell you how much by or anything though :/
Luckily my front wheels fitted fine without using spacers or anything. It was the rear ones I had a problem with.
I had to take a few mm's off the brake calliper though using an angle grinder. I just kept taking a tiny slither off until the wheels didn't rub anymore. Now I have about a 3mm gap between the calliper and wheel. I'm also using 5mm spacers on the rear as I didn't fancy grinding a lot off it!
To to bring the rear wheels in a bit more, you can also swap your stub axles to the ones from a 172 like I did. They are about 5 or 6mm difference so it's worth doing
If you need any help I can post some photos up here if you like.
Dan