I have two of these machines and could not live without them.
They are not the digital units and could be twenty years old or so.
I bought replacement circuit boards for backup which are very spendy
and perhaps unavailable now days. The other backup part you may need
is the temperature sensor that regulates wax temperature. I have had
little problems with them.
They may not be necessary for basic wax injection. I use mine for
rubber, silicone and metal jewelry molds. The vacuum part is many
times unnecessary, but a must for many of the filigree wax pieces I
make and cast.
For basic wax injection I air pressure wax pot would be more than
adequate. I have never cared for the pump pot that has the wax shoot
straight up from the air piston; you can hit the ceiling with wax
with those units. But any of the air pressure wax injectors are a
standard form most mold injection.
You could probably sell it for the price of a new air pressure one
on Ebay. I also have a jewelry friend who is looking for one if you
decide to sell it. Let me know. Gesswein used to service them and
would be worth a call.