That's a 748/916/996 series superbike frame, and that is the stock swingarm and rear wheel from a 748 or 916. They had 3 spoke wheels for a few years as the "base" wheel. I have a set of those wheels and a spare 748 frame in my basement lol.
EDIT: Correction...that motor is weird though. The vertical cilinder on a ducati superbike motor is just that...vertical not slanted back like that?! So it LOOKS like a superbike series frame and rear wheel...but now i'm rethinking it lol.
Yup not a ducati...I was wrong lol. For reference here is my Ducati in it's current state lol. Picture is a similar angle but I have the R spec 5 spoke Marchesini wheels.