Have 2 electronic distributors , Mopar and Petrinix

It is a 1970 that was converted to petronix electronic , don't know what was changed as just bought the car 1 month ago , will change the voltage reg just to be sure , is there a way to tell if the regulator in now is electronic or mechanical , does the petronix work with mechanical voltage regulator ? If it does could that be the problem now as Mopar electronic ignition needs new electronic regulator ?