My Dad bought a CoOp E4 and a Cockshutt 50 both motors were locked up and both were replaced with motors from Allis Chalmers combines.  I've got 3 blocks and only 1 has the tag by the distributor.  All are locked up so there is no chance that I can measure the stroke.  Where can I get information about which motors I have?

The one in the tractor sat for a year and magically gathered 3 coffee cans full of water in the crank so it is now locked up and I'm trying to get it free again, but eventually I want to rebuild one for use and occassional vintage tractor pulling.

The engine in my tractor now is missing the identification plate and has the following numbers cast into the left front of the block

4 850
45121527 (this number actually has the last 2 leters ground off)

You can tell that it used to be 4512154x. Not sure what the x used to be but you can make out enough of the 4 to know that it was there before it got ground off.

There is another on in 'storage' that has these numbers cast into the block
      4507922
          32
         588

And the third and final motor still has the tag on it and it reads
Cockshutt at the top and the engine serial number was 363050.

Thanks any help with this would be appreciated.
-ron