Auto Trans Gear indicator- how tp keep aligned with only 1 screw?

[WinDancer]

I have a 69 GMC with a T400 trans.
I had the trans replaced last week and now the shift indicator won't stay aligned.

It has a single screw in the very back end that doesn't appear to hold it even when tightened.

The back stays aligned but when you shift the front gets kitty-wampus off to one side or the other.

I spent a couple of hours and now I give up.

The screw mount in the indicator itself is cracked, if anyone has an extra indicator for a standard auto column shift.

How do they stay aligned?

Thanks,