[Boatanchors] Tube tester

[LARRY D GODEK]

I have uncovered a Weston 798 tube tester. It works although the adapters for testing some tubes are missing.  Otherwise its in excellent shape, not NIB of course.  Anyone know anything about it?  I have a pictue of it if anyone wants to see what it looks like.  Came with charts charts inside.  Original type written charts.
 
I've never heard nor seen one of these before.  Wonder if they were popular or just a few made and if for non-ham use, who was their main market.
 
Larry
W0OGH