I'd have to say a pro is that it's a rare car.
Its being rare also makes it a con.
I will assume that a 510 has more interchangable parts with other cars than a 1200.
I like the fact that you can't just open a catalog and find anything you want.
It's a challenge. You have to research. You have to go to the junkyards with a tape measure. You have to understand why speed parts, easily available for other cars, work and how are you going to adapt it to work on a 1200.