Do old guitar tubes have any value?

I'm not sure if this is the place to ask this question.....I'm new to the forum.(no flames please)
I have laying around 2 sets of 2 matched and hand signed GT-6L6GC Groove Tubes that were made in the USA. I purchased them in the mid 80's and were rarely used.

I also have a matched set of 6 Sylvania 6L6's from the late 70's or early 80's. I used the amp for about a year and has collected dust ever since.

Do these tubes have any value? Comment would be appreciated.
Thanks

There are businesses that specialize in selling tubes for guitar amps...

1. Amplifiers, Amp Tubes, Guitar Amplifiers - Cold Springs Electrical Works - Amplifiers, Vintage Tubes, Sprekers, Amps and Guitars

2. Hi Test NOS Tubes
341 Westwind Court
Norwood, NJ 07648
201-750-2445

There may be others, but these two advertise in Vintage Guitar Magazine every month.