Hi: The Heathkit, Eico, Paco and Knight (Allied) VTVMs all had bannana jacks and probe cables of rubber, that cracked over the years. I recall one meter with the old microphone screw coax perhaps for AC input shield.
The VT bridge circuit seems to limit meter movement (200 uA?) overload, I never had damage to the movements even with extreme overload.
IM-28 were the newer series but basically same as the VT-7.
Hope that someone can please post a link to the Zener or LM317 battery substitue circuit?