This a NOS socket  for these tubes, in good shape.
Consisting of a base plate  for both tubes, and a ceramique chimney  for gu84b only.

I have used this socket for testing  and preheating  NOS tubes before mounting in the amp.
Picture  is available.

Any interest ?  reply off  this list  .  My email is ok on my qrz page.

Asking  70 Euro   + shipping.

Dirk on4ct