Early 1960’s MF35

Good morning! I’m new to the group but, I’m starting with a question. My MF35 is a 3 cyl Perkins. It is an early 1960’s (I think ‘61) model. I was wondering if anyone has some wiring information for the manifold heater. Is it wired from the starter or from the ignition switch? If so is it wired for continuous or just in start? Any help would be great! Cheers!