Can you skim a few mm off the inside of the wheel like I did yo increase the offset. Been running mine now for quite sometime and miles with no issues.
I asked JBW about that and they don't recommend it, which doesn't mean I won't do it if pressed. But pulling 5mm out (which i'd regard as a max) will only take them to 27, 1mm less than the MGF 15s.
I've also been looking at tyres and I can easily get 185/60/15s in a range of makes and speed ratings for sensible money. Toyo Proxes CF2s are £52 a corner and Falken Sinceras are £58 a corner. There are no name specials for under £40 a pop but i'm not THAT hard up! The tyres on the Dolomega currently are 185/60/14s, so i'd basically be lifting the car a 1/2", but no other change to aspect ratio or compliance from what I now have. I already have an electronic speedo, so calibration is only a matter of a single measurement (rolling radius in inches) a couple of quick sums and punch the result into the speedo.
The Carledo ran on 195/50/15s and I had to relieve the arches a little bit to get them in, but a narrower, higher aspect tyre might negate that a bit.
I've also found a set of F alloys on ebay in a style I quite like (6 blocky, parallel spokes) WITH tyres for £120. The tyres have decent tread but are the usual MGF combo of 2 x 185/55 and 2 x 205/50. But I could TRY the 185/55s on the back and see how it goes, before I spend money on tyres, something I never thought to do on the Carledo in years gone by. Might also be possible to shave a couple of mm off these too.
I'm not terribly worried about the weight of the F rims, it didn't seem to noticeably upset the Carledo, but then again I expected harsh and noisy from that track focused car, so wasn't surprised when I got it! But it didn't have bump steer or any of the other nasty side effects of too high an unsprung weight.
I can also sell on the JBW fake minilites to someone with a TR7/GT6/Spitfire/Vitesse/Moggy Minor etc which WILL work with the 22 ET. they've only done 1300 miles from brand new, tyres as well!