[R-390] Source for URM-25 MX-1487/U impedance adaptors?

[w4qg]

Hello All,

I receintly got my URM-25/E (uncommon variation - I understand) 
up and running at 100%. One of the first things I want to use it for 
was to do an alignment on my 390A. Well, I have most of
the accessories but I am missing the MX-1487/U impedance
adaptor. Does anyone know if a source for these?
I'm sure I could whip something up that would work, but now
that I have a nearly complete, fully functioning 25/E I wanted an original.

It was lots of fun repairing that 25/E, it had the common problem
with the modulation (dead), those caps on the audio board are a 
real bugger to replace. Works beautifully now...

Next I start on another 390A that is dead, more on that one to follow,
it is an oddball (ITT nameplate, extra position in the function switch,
looks to be all Collins sub assemblies inside...)

73,

Paul W4QG