How To ID Prestolite vs. IH Distributor???

I have checked for a tag or other identifier, but find none. Can anyone tell which it is from the following clues???:

1. Cap is held on by spring clips;

2. There's a sort of "cover plate" under the rotor that hides the points;

3. The condenser is clipped to the outside of the distributor (condenser end says "972002 DR");

4. Inside cap says "Made in USA";

5. Coil & condenser wires attach to a plastic "cube" with screw stud on outside of distributor;

6. Tractor serial number is "19359 SJ".

Are any of these things identifiers? Is there any other earmark that would identify which I have?

Thanks very much for your help.

Bob Kirk

Again, thanks very much for your replies.

Bob