Nice little blast-from-the-past , CuriousCollector .
Gretsch Co. was formed in 1883 .
They mostly manufactured guitars & drums/drum sets , although they did have several product lines for other stringed instruments .
Depending on the condition of the strings , they have a somewhat small value , except to collectors of Gretsch do-dads , IMO (& I would sell the whole box as one unit) .
If you sell them for actual use , I'd add on a disclaimer concerning the 'playability' of them .
The Gretsch company is still in business .
If you had some vintage Paul Bigsby stuff , it would draw in quite a bit .
Paul Bigsby , Chet Atkins & George Harrison were among MANY famous guitarists who chose Gretsch guitars as favorites .