That's how you wind up with 100 tubes sitting in a box. 
Yeah but in 50 years your investment might quadruple.

But seriously
I'll let you know tomorrow when I'll have some time to play with my toys. (if not tomorrow then Tuesday)
I bought $99 pair for my Consonance Droplet 5.0 CD player. That player came with Sovtek 6h30 NOS. (I am keeping those too)
The one from 94 was intended for Dodd.
Which one to get is your choice.
Premium tubes from this family cost between $35 and $50 (with few exceptions)
It is only one tube - what a heck you have to loose? If it was good for Siberia's nuclear missile bases, spy satellites and other space junk, it should be fine for little Dodd buffer too.
You might also check/google forums discussing these tubes in Audio Research or BAT gear.