The first is as noted is an RMG series, which came in a short 9" eff length 212 model and long 12" eff 309 series.
The one shown does have the original 7 pin din out of which 2 of the pins are not used early version.
Oddly enough "some" of the RMG-212 versions were made without the rear stub rubber coupling
although I can't say I have see this in the RMG-309's.
There was a RMG made for EMT that like the early SME series 1 had the rotatable collar diamond versus square configuration.
Sorry for rambling on the coffee is kicking in.