Thanks Jeff, That looks like a good example. I am looking at the unrestored pictures of the orange Metuchen H code Mach1 and it looks like it has P&O on all four bolts. But a closer look, it has a 24" radiator and being a 2V and no AC I think it would have the 16" radiator. So maybe the rad was swapped out and the bolts changed? Or maybe they are just dirty corroded bolts? Alan