Bill,
Don't give up!
I have seen 4 Masers over the last 11 years on the surplus market.
The EFOS2 (active) that I had the pleasure of playing with for many years. (working great)
A VLBA112 Sigma Tau Maser (active) That I had for a couple years. (non working needs a lot of care)
A Kvarz CH1-76A (passive) that I still have and works
A prototype passive maser that I've been babysitting for a friend while I try and see if it's repairable.
Of course an active Maser will eat up some space, not to mention electricity and consumables (vacuum pumps and Hydrogen)
Cheers,
Corby
Trying to add a PIX of the EFOS2, if it does not make it I'll resend from home later!