I had a very similar setup, although mine was a D6.
And I was very happy with it.
At one time, I was able to get a footswitch for it that KHB put together - the challenge being the old style English connector.
While I expect parts can't be particularly easy to find, the head is probably serviceable with a hammer and a chisel, and I wouldn't be surprised if the controller parts were discrete and plentiful.
And the styling reminds me of old Nanaimo .
A move to smaller premises mandated a sale of my 4x5 enlarger, or I would have happily continued with it.
It's pretty good, the grade spacings are odd on the original controller (as it matched gen 1 of modern multigrade). It can be run with the correct adapter (i.e. if you have the plugs and schematic) off an MG500 PSU & controller, if it has the voltage tap for the 500HLZ head.
Alternatively, if you are prepared to work on a split-grade methodology, you can run it off suitable power supplies directly.