I have 3 double albums released by Fantasy in 1978. Each one has 2 LPs each.
They break down like this.

"1968/1969" ---"Creedence Clearwater Revival" and "Bayou Country" albums
"1969" ---"Green River" and "Willie & The Poorboys" albums
"1970" ---"Pendulum" and "Cosmo's Factory" albums

I guess they're promo copies since there's a whole punch in the upper
right corner of each jacket. Are these of value or just old crap I've kept.

I remember these. To be honest, I can't imagine they'd be worth much on the collector's market.

I've got a ton (literally, I'm sure) of vinyl still in the Archives. I'm afraid it's mostly worthless these days.

I knew that Jimbo would know! My father in law just
got some free vinyl. He loves CCR.

Beatles, Hendrix, Dylan, etc, then 60's-early 70's pysch and prog, then certain labels( Vertigo, Elektra, Island, Harvest, etc), then Mono or Stereo are were the big money are/is, vinyl-wise.

After that '76-84 punk/postpunk is the next fertile period.