You could substitute 75735 for the 75730, but you will need to break off the 87A leg of the relay. Waytek has 7344 of those available
break off the leg pointed out in pic
Edit- you don't have to break off the 87a leg of the relay - the relay panel has a slot for the leg, but the 87a is not used in this application.
important-Pin 85 has to go into upper left hand corner slot on relay panel- relay may not be printed the same as the 75730, so not sure if relay printing would be upside down or not when mounted in relay panel.