Should I update a vintage 16" broadcast transcription turntable?

I obtained a 16" Gray transcription turntable from the CBS Radio studio in Chicago some years ago.  It has 2 vintage tonearms that cannot accept modern cartridges without substantial modification.  It also has a massive motor, platter and spindle assembly.  It spins but I'm not sure about the accuracy of the speed.  I am debating whether it is worth the expense to modify this turntable to modern standards.  

I would need a new tonearm - not sure if a 16" or a 12" would be best.  I also am not sure whether the existing motor provides accurate speed control and likely would need to add that capability.

To do both would probably cost over $2K.  I currently have a Yamaha PX2 TT with a Hana Umami Blue cartridge.  I also have a Technics SP15, a Lenco L75 (needs restoration), a Transcriptors Skeleton (has a glass case), and a couple of Sony midfi tables.

I'm looking for input whether it would be worth pursuing the modification vs selling the table as is and buying a more modern TT.  I am satisfied with the Yamaha - it is very convenient - and want to either get the Gray to a functional state or sell it.

All opinions are welcome and thanks in advance.  I live near Atlanta and am open to a mod shop within driving distance.  The table would cost a substantial amount to ship.