Well a 225 mm tire is approx-8.9" wide at its widest point (not the tread, that will be narrower) a 10" wide rim is generally 11" wide at its widest so about 1" of mismatch on each side, will give fantastic lateral stiffness to the tire and look like crap IMO.
Personally I'd be looking for different rims, maybe even a steel 14" set that would fit some of the modern LRR tires but I know this would be completely against the character of the car and is not likely to happen unless you get a little further into the FE sickness that spreads here
