I bought that motor because it seemed too good to be true. It is in great shape, is "period correct" for my buggy, was the only rebuildable brushed motor at the whole swap meet, and it was $5. I didn't know the wind. After a couple of figure 8s in the driveway to check the steering and listen for unwelcome noises from the transmission or elsewhere, I pulled the trigger. Instant backflip! The car actually ended up behind where it started.

No forward movement at all. It just rotated around the back tires.

Luckily, nothing was damaged. I went to the interweb and discovered that the "Diamond" is a 12 turn double!

I was thinking a 19 would be about right, with a 17 on the extreme end but still acceptable.
I haven't worked out the paint scheme yet, but one of the colors is white so the white motor will stay. I will just have to be gentle with the throttle.
Body and wing are next.
The springs, even though they are the ones I had on it way back when, are obviously not going to work. Just bouncing the chassis on the workbench proved that. I will play around with oil and maybe pistons, but I think I will end up replacing them.