Early VacuMaid
Hello,
Regarding whether or not this is a VacuMaid valve, I'm 99% certain that it is. These photos are from a late 60s home here in Pittsburgh (Where Ed Lindsay hails from) and had an original P245 unit (uses a Robinson Myers motor. Think Early Hoovers) and 4 of these inlets throughout this home. These super early units didn't use cyclonic action like the later VacuMaids, instead they had a spinning separator much like a Rexair. This unit's motor had been repaired numerous times by the original purchaser before the home was sold and the new owner's had us install a bagged VacuMaid to replace this unit.
The photo posted of the stainless steel VacuMaid valve was their later iteration of their own inlet, which is still made today in various finishes. Although I do like the appearance of these inlets, they have the largest footprint (Not great from a non-cv aficionado stand point) and because of their all-metal construction, if you opt for the pin-jack version, the metal body is prone to shorting the system and causing it to run if the wire is even slightly out from underneath the contact screw.
Regarding installing this inlet, you may want to just take a standard mounting plate and drill new holes in the plastic where they would line up. Thankfully mounting plates are cheap and if you ruin one, you can always try it with something else. Late last year I updated an entire home of these old VacuMaid inlets with new VacuValves (homeowners wanted on/off control) and although we did so without cutting out the mounting bracket, the screws definitely went in at an upwards angle to speed nuts that lined up perfectly with the old VacuMaid inlets.
Fred: I definitely agree with you about the durability of the metal valves on your system. They do hold up beautifully and some people love the metallic finishes available to make them really stand out in homes. I have always been a fan of "pin-jack" inlets, as VacuMaid refers to them, as I find them to be much more reliable and give you the ability of using a hose with a switch in it. I've been called out to service several VacuMaid systems that had their ball stuck (I hate when that happens) in the switch, causing the system to run continuously. I don't know if it's more annoying for me to go out to the home for a pointless service call or for the homeowner to have to pay for a pointless service call. As you mentioned, they are very expensive, and although some like their conspicuous appearance, many people want their inlets to just disappear into the wall so we tend to use VacuValves which just look like an electrical outlet blank when they're closed.
