Hi Duncan
10:40 or 15:40 will probably be fine. I suggested millers 20:50 as that is what i was recommended and the info on the millers website seemed to taly with what i was told.
this is what i was told for A & A+ engines.
15:40 or 10:40 will be fine if the engine is still fairly tight, ie upto about 30K unthrashed miles. if it has done much more than that i would recommend 15:40 upto about 50K and 20:50 over 50K
http://www.millersoils.net/1_Millers_fr ... RSPORT.htm
CTV 20w50 was designed for high performance MINI engines.
With regard to the mods, from the photo, as you say it looks fairly standard. The main things that stand out to me is the colour, the wheels, the steering wheel & grill. As Paul said, the wheels look smaller than 13" but that might be an optical illusion, however 10" wheel mods was a very common mod to Jap cars so i believe.
You can get a full genuine SU turbo rebuild kit from mini spares center.
i think the main thing to change is the needle valve to the float chamber. Paul might be able to give you better advice on this.
I didn't mean to scare you off using yours on the track with regard to the heat. you can pick up heat proof/reflective fabric fairly cheap if you need it. when you get yor car, have a look under the bonnet and just check that the fabric in in place on the bulkhead behind the turbo and on the hoses in the vacinity. if it looks ok, you should be fine.
As soon as my engine has been built and run in i will be giving mine a good thrash
Regards
Darren