The amount of parts, grease, and flair you receive from a restoration item varies. I've seen a difference of at least 50 grease on one item between the most and least I remember seeing. I don't usually pay attention to the part and flair numbers as I have more than I'll probably ever use (you seem to get significantly more parts than grease from most items).
You get a ton from these. Highest in the game that I've seen. They're a great flip with a high resell value, but if you need to build up your stock for other projects, scrap it!
Not a recomended restoration for low level shops because it can leave you broke and it takes a ton of grease. They also take a LONG time to restore, and will eat up most of the floorspace in your back room. In fact, it won't fit unless you have expanded once or twice. Fits in the default parking lot but you won't have room for anything else besides a side-by-side motorcycle.
Some cool design options like flames or green tribal (on the black paint).
I wondered the same so I used one for parts. I got:
4842 parts
162 elbow grease
1 flair
Comparing to the 32k that I paid for it, it wasn't the best exchange