Flywheel/ clutch inspection plate

[KC Tom]

Removed starter on my 1940 Lasalle to replace solenoid and while I had it out I took it to a local shop to have it checked out. They said it needed a new drive so they installed one. I reinstalled it the drive gear exploded for some reason. They did mention that the drive was not coming out far enough so they adjusted it.
Don't know if they adjusted to much or installed a wrong drive or what. I was able to retrieve a piece that was about 1/3 of the gear and three other teeth with a magnet but there is more debris I'm sure. Is there an inspection cover I can remove to clean that up? The car has a diaper so I can't tell.

[wheikkila]

Yes, there is a cover on the bottom that can be removed and clean out any items. My question is what damage was done to the flywheel?
                       Thanks Wayne 

[KC Tom]

Don't see from above but will have to check when I remove cover.

[fishnjim]

I don't think engaging the starter would cause that.  It would have to engage while the engine is turning to shatter the gear.  Expect flywheel damage, too.   
I'd be looking for parts.

[KC Tom]

Removed the inspection plate today and the flywheel has very little damage. The very top of a few gears were slightly rounded. I believe they will work.
My biggest concern is why this happened. Could the solenoid have stuck?