Seat is aftermarket (obviously). Looks like someone cut the rear of the frame off. Tank doesn't look like it fits right, should be lower in back? Or might just be lack of stock seat... but if I had to guess, the carb set up isn't stock and the tank is raised to clear it.
Front hub has been cut up? On second thought... it may be a non-Ducati hub, it looks like there's a brake stay visible on the other side which wouldn't be there on the stock part. Rear sprocket looks weird too but that could just be an aftermarket part. Fork tubes have been painted (between the triples) headlight mounts are missing (and expensive if it's got clip ons). There are some spring covers that are missing too , replaced by gaitors. Headlight's obviously missing so the speedo is gone. Wiring is non-existent. I can't see what's being used as rear sets but the stock pegs are gone. I don't see a kickstart lever and who knows if the kickstart internals are still there.
If it's a 175 don't expect much for performance. The 175 is the same family of engines as the 250 though so parts are for the most part readily available. It's not a desmo, if that matters, which it shouldn't.
The good news is, that's a desirable tank and overall I'd say the bike could be the basis of a pretty sweet little project. It needs a lot to be streetable but I'd be happy to start with that.
I'm guessing whoever put it together was shooting for this look... which is a project I had in mind too. I've got the engine, tank, forks, and front hub. The rest is still out there somewhere...
I noticed the rims are mis matched. Non stock Alloy front and possibly stock steel rear. Front brake may not be stock either as it is heavily vented and thicker. looks like a borrani or akront on the alloy rim)
Not familar with the intakes but the carbs look to be on a longer intake manifold and at a different angle from stock.