From the bottom you get a hint that something is different:

I got the chassis on ebay. I wasn't told that one motor mount had broken off or that the rear bushings were heavily CA'd due to chassis damage. I salvaged what I could and tossed it in junk box. :(
The open-frame motor also came from ebay, in a box with a bunch of stuff. All it needed was a bit of cleaning and a drop of oil and it ran fine. But I had no use for it, so it went into the parts bin.
Then I have no idea why, but one day while driving to work it hit me. I might be able to put that motor in the busted chassis!
The Dremel got a good work-out, but I think it was worth it:

The slots that holds the bushings were cut way back:

And portions of the chassis were trimmed to allow the motor to fit and to float:

There are springs in the new mounting tabs:

But after trying it different ways, it turned out that it ran best when the screws were tight.
It runs OK on my 45' Carrera track, but not great. It's slow to accelerate and never reaches top speed. I don't recall what the gearing is, but it's nothing extreme. I'm not sure if it is the gearing or the motor. I don't think it's my track power, it can supply up to 5 amps. I'd change the gearing, but I only found one pinion and one crown that fit.
All in all it was a fun project. A great way to kill some time.
Oh, do any of you know what motor this is?
Thanks,
Ron