"If it's the right thread & the right shape then it's the right nut."
Sound advice. The PCD of our hubs are shared only with MG /Austin Rover products such as the MGF and Maestro / Montego so the threads may well be unique as well. Which style of MGF wheels have you got?http://www.mgf.ultimatemg.com/group2/suspension/wheel_options_for_the_mgf.htm
Someone here may well have the same wheels fitted on to their 7 and tell you which nuts worked for them.
Adam
TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991