Solved -PJ443- Restelli Tipo R 12/15 hp 1920

[Wendax]

Well, the few of my books mentioning Restelli don't mention a model name, and on the net I just found 1500 what probably isn't the name you are looking for. I just can guess: 10 HP?

[Paul Jaray]

The prototype of 1915 was a 10hp. There was a 12hp and this one...
Still locked for you.

[Wendax]

14 hp?

[Paul Jaray]

Not 14.

My source calls it 12\XX HP Tipo Y
If you do not have a source I leave you a further guess with a clue:
XX: bigger than 12, but not much.
Y: it was the sport model but it's not 'S'.

[Wendax]

12/15 HP Tipo C?

[Paul Jaray]

12\15 hp is correct.
I would have said Tipo C too ('C' for Corsa), but it's R!
No need to go through all the alphabet, you found the car!
And 601 will be. 

[Wendax]

Thank you