Uncle Rod knows his stuff on SCTs and probably Celestrons in particular. He's the CAT guru.
Now lets get to up front and current. What you have IS a Celestron Ultima8, C8 OTA that has been removed from the forks. Here is a picture of mine and they are identical down to the rear cell mounting holes.
Yours has been removed from the forks. The dovetail rail was added. The reason you have the small finder is that the original one is a bit special illuminated 50mm Polar finder. That finder was probably kept by a previous owner or sold for a premium. You can see it in my picture.
These are indeed nice scopes for optics. The entire original mount, wedge, and tripod are very robust things. When Celestron jumped up to this model, there is a reason it was called the ULTIMA and the name fits. This model was Celestrons response to consumer request for a beefed up version of the C8 for photography stability with attention to excellence. I do not know for sure, but I've heard that Celestron favored this model for choice optics during assembly. Perhaps U. Rod or some one else can comment on that. I have a few Celestron C8, well had 3 ornage tubes at one time, still have one orange and an orange C5, and Meade LX200 8" GPS SMT UHTC NBC CBS and ABC. The Ultima just sneaks in better optical performance that ALL of them in my case.
Want to buy it? I have to let it go, I just have too many scopes. (yep, I said it!)