It might also be worth taking apart the pump (just remove the threaded valves and inserts) and soak it in citric acid for a bit. It will probably still need a rebuild given the condition of the machine but you might get it functional at least for some testing.

It's a fluid-o-tech
I will take it apart but I just got to Cabo San Lucas so it will be a couple of weeks
Sorry but not really..

So I pulled the heating element today...
This is what I found...






I was expecting scale but not brown.

Oh man!

What's the best way to test the heating element?

Hi Doug! What an awesome thread developing!!

I believe you could set a multimeter to Continuity/Ω Ohms and probe the two contacts of the heating element and you should get between 8 and 15 Ohms

Here are a few videos of tests on two different Heating Elements (be sure to unplug the machine so you don't have to relearn the alphabet or get your fillings put back in) . . .

(1) Nuova Simonelli Oscar 1 Heating Element test (maybe mute this first video, the camera refocus clicks a lot, apologies):
(2) A Bezzera Magica S HX Boiler Heating Element test:

To get the pump going you could place it fitting-side down in a small pot of strong citric acid (or other descaling solution) and use a hand drill to cycle the pump every 10 minutes. Don't submerge the whole pump but just enough to cover the incoming and outgoing openings. I'd do this for a good hour and having it in a pot on the stove to get the citric acid at around 60-80C will speed things up.
Doing this got a clients pump going again but ultimately had to be replaced.

Brilliant post by trumz just above about the pump revival! Should work if all the vanes/seals are intact and if not a rebuild will definitely make it new again!

Thanks very much for that information

Hi all, I haven't posted in awhile and wanted to post my updates and help now required.
Since I last posted, there has been lots of work done on this machine, new pump, Sirai, rebuilt steam and hot water valves, and pressure gauge. The biggest however, was the boiler. It had a hole in the heat exchanger and I had the heat exchanger replaced in it. The entire machine has been descaled.
One thing worth noting the thermal reset was missing and was bypassed by a previous owner. It has now been restored
I've got the Mac put together and running, it heats up, and the pump works. All of the volumetric controls appear to work but need reprogramming.
Here's the problem I'm having: when I turn the machine on it seems to work fine( the pump fills the boiler and the boiler heats up). Once it's warm, the machine will deliver water through the grouphead fine.
The pressure gauge for the boiler reads zero and does not seem to be building any pressure. Nothing is coming out of the steam valve when opened and hot water dribbles out of the hot water valve but very slowly.
There is no audible hissing sounds coming from any of the boiler circuitry so I'm not sure what's going on
I bought this machine DOA so I dont know what its state was prior to me tearing it down.
Any and all comments are appreciated
Thanks Doug