Indian Seat Tee

[rms337]

On the '40 and later seat tee's, some have a single hole and some have two holes for the seat post mounting. I assume the two holes were to accommodate different models, but not sure. What years would have had a single hole and what years would have offered both?

IMG_1491.jpeg

[rms337]

Bumping this post as I am at a point where I need to make some decisions on which one to use. Can anyone help with this one?