I would give it a go to see if you can remove the threaded port on the solenoid. I would try to put the entire contraption into a good bench vise, and then try to torque it off with an appropriate sized wrench.
There is a seller on eBay that is selling the Parker H3L brand new, with shipping for about 30 USD. This is less than the Fabco that you are looking at.
Hope this helps,
I searched Parker H3L and it didn't come up, DB. There's one for $75 + Shipping. Could you paste the item # for me?
Moose, I have the parts to change the fabco's input side over to 1/8 npt but don't have what you need for output side. Let me know if you want them.
Ok, less insanity here today... ugh... So if I understand you correctly, you have the part that screws into the bottle-side of the valve. That would connect to the output of the solenoid. I would need a short tube threaded on both ends to do that, right? I think I have that! Let me know what you want for it OP.