[Milsurplus] puzzler - module with glass rod?

[KD7JYK DM09]

: Way too big to be a SAW device, methinks.

Yes, BUT...  Look how it's designed, how it's labeled and work back,
technology wise, a good chunk of a century...  Think of the first
transistors compared to the ones we have now that are measured in size
comparable to wavelengths of light.  Could be an old, inefficient and low 
frequency SAW filter.

Kurt