A clear photo of the distributor BODY would be helpful, as it could have the incorrect cap......but none-the less, the shaft top with the cutout for the rotor indexing indicates to me that it is a Holley distributor, and the reluctor wheel specifically a Gold Box electronic type, which has been modified with a PerTronix Ignitor III unit.
For this unit to operate, it needs the following: PerTronix magnet ring, Holley rotor, Holley distributor cap.
The Prestolite distributor shaft has a "D" shape at the top to index the rotor.
....and of course the GM/Delco unit is easily identified as a GM/Delco by its' 360° rotor (retained by two screws), as anyone who ever touched a Chevy or GM of the 50's or 60's or early 70's would recognize.