M7 is not common at all. Not here in Germany, not on german cars. Maybe on some machines it is common just to make sure that the bolts won't be changed or swapped with a worse quality, I don't know. But on regular cars and other things that need maintainance there's no M7. I really had problems to find M7 bolts when I had to drill one out. If John sells them and has them on stock - perfect ! Elvis PRV is a very old design (1971). At that time 7x1mm may have been common. Perhaps a metric old-timer can verify. 8x1mm thread on banjo bolts is also rare now. Bill Robertson #5939