I assume your Unistar Deluxe is equipped with a saddle. My Unistar Deluxe saddle came with two sets of jaws, one to fit Vixen (V style) dovetail plates and another for the wider Losmandy (D style) plates.
Your A-P is a fairly heavy refractor at 18 lbs for the bare OTA, and its 5.5” rings should be equipped with a Losmandy style plate. I can recommend the ADM DUP 11M-D Universal Dovetail with 60 mm spacing, which is what I have on my GTX. It is significantly lighter than the A-P 12” dovetail (SBD12) which has a taller base to clear the dew shield on some other scopes.
Hope this helps.
Edited by lionel, 07 July 2020 - 03:01 PM.