[john walker's workshop]

Best to use a '69 case. There's not enough material in the area where the '69 style fork pivot ball would need to be mounted. The '69 and earlier pivot ball is closer to the guide tube than the '71/71 ball, and the fork is different. On the outside there's a casting that looks like you could just drill another hole, but inside, there's a depression milled in that spot, and a steel insert. I suppose you could have it welded up. Then there's the side cover difference with the loop that the 70/71 cable slides through and the early cable sheath that fastens to a small hole in the protruding tab.