Good video-thanks for link. I don't mean for my reply to hi-jack your post, so I change subject line slightly.

During the late 50s, early 60s, the tandem hookups were popular in our area (NE IL). However, we had nothing as sophisticated as Monroe hookup. They were mostly known as piggy-back tractors here. Some called them double-headers. Everyone here drove from the front tractor. Nothing as sophisticated as the Monroe rear-drive. A local welding shop helped build ours. I think '58 was it's first yr. Ours started out w/a JD720D on the front w/an IH SuperM on back pulling Oliver 6-16 pipe plow. Following that, came an IH560D on front, then finally a JD4010D on front...still SuperM on back. On ours, the SuperM was also the mounted picker tractor (IH 2MH), it was also the loader tractor, so it had to be "quickly" dismountable to do all the jobs. The back tractor was hitched to the front with just a pin thru the drawbar. The hydraulics were operated by the front tractor. So, you just had a hitch pin & 2 hoses coupling the 2 tractors.

I'd say the JD4020 finally ended the piggyback reign here. Most guys could pull 4-5 bottom OK w/4020 & that was the first mounted plows for most here. Made life much easier. I can see that Monroe's hitch would've been much easier to steer sitting on the back, though I assume visibility was a problem.

1st photo below is our piggy-back as it appeared in 1958. That's brother Larry sitting on 720. Sorry about Polaroid quality. Second photo is 1/64th scale copy that my son built of our setup. He built the tractor about 7 yrs ago. A gentleman in MN custom-built the Oliver pipe plow for him. Bobby Greif (veteran NAT poster) supplied the literature photocopy for the builder to use. Builder had never seen pipe-plow.