I've mentioned that I'd use a Honda if I ever needed to replace a missing pony motor. I guess it worked for someone. I can't tell if they have the exhaust preheat hooked up though. https://madison.craigslist.org/hvo/d/milton-1947-caterpillar-4/6862193837.html
I have seen either this one or another like this before. The pony motor is still their. The one I seen had the rods and pistons removed from the original pony and was just turning to use the pinion and starting controls. It had a v-belt pully secured to the existing pony flywheel and simply tightening the belt turned the existing pony. No heat, they just take a little longer cranking under compression to warm up. That D4 has a PTO and the Cat 44 front hydraulic unit, both desirable to the collectors.
That's very kool..
7U with solid idlers.
where there`s a will there`s a way
I worked on some 12V71's on big drilling compressors that were set up with a belt driven Bendix starter drive and used a 2 cylinder Wisconsin with a Rockford clutch to start them. Worked great when you could make the Wisconsin run. later I was commissioned to put electric starters and a charging system on those engines.