Help identifying generator mounts

[ndnchf]

Can someone help identify what these generator mounts go on? Both are 8BA type with similar cast in part numbers, but they are different.

8BA-10153C. This one has the alignment pin fairly close to the center of the bracket. It is also wider looking at it from the side. This one seems to be much more common.

8BA-10153. This one has the alignment pin close to the front edge. Overall the bracket is narrower looking at it from the side.

I restore generators and know them well. But still learning about the different mounts.

What is each one for?

Thanks