Generator tension brace assembly

[ckulchar]

Can anyone provide a part number for the correct v belt used with this brace, Mac's A10152? Most venders offer the same brace. I've tried a number of different belts. Can't get the slotted part of the bracket to align with any mounting bolts on the engine.

This is for a 1931 with the stock generator.

Thanks in advance.
Charley