I have 15x6 Panasports with 195/60/15 Yokahama AVS ES100s on my 72. I am very pleased with the handleing and do some track days and autocross with it. This is what's refered to as a plus one fitment, the stock size being 185/70/14. The only problem that may occur is with the offset of the Panasport rims. They are offset more to the outside of the car than the stock rims and the tires may rub the rear quarter/ wheel lips. On my car this was caused because the original rear axle was offset to the left side. I swapped out the rear for one that was centered and have had no rubbing problems since. This apparently was a quality control issue with the factory. If you are contemplateing Panasports, I would carefully measure your present clearance on both sides of the car to see if your axle hsg is centered. Moss also sells a replica minilite that I believe has the correct offset. The catalog says they are a direct fit but cautions to check clearance with the panasports.
Now to add to the confusion, you have a wire wheel car. This means your rear axle is 1 1/2 inch narrower than a disc wheel rear. You can bolt the disc wheel hubs on your rear but will need longer wheel studs and spacers to get the right offset. This could be an advantage with the Panasports because you would be able to dial in the exact offset you need. Of course the other option would be to swap in a complete disc wheel rear. And still yet another option would be the Knockoff minilight replica made to fit wire wheel cars. They are rather pricey though and you still have to deal with the splined hubs.
Hope this has been of some help and not too confuseing. just holler if you have any questions.
BTW, just for general info, The 14" Panasports absolutely do not fit a Chrome Bumper MGB without modifications. Evidently the people at Panasport think just because a rim has the correct bolt pattern, it will fit. This is probably why Moss warns to check for clearance. I'm sure there have been complaints. Don't get me wrong. They are a very high quality rim and I have 2 sets, 15s on my B and 14s on my TR8, and have been very pleased with them.
72 MGB 80 TR8
Pittsburgh PA