Well, I might have it wrong. I was actually restoring vinyl that was recorded in Portland from '50-52 or so, but was told they also had some 1/4" reels from the same era.
I was doing other things with my life when I should have been working on tape, so I'm not sure they have the format right--it might be 1/8", and I just don't have that experience. I just made the assumption (and we all know how that goes) that because of the age, it was probably something uncommon. I haven't seen them myself.
Would that have been a popular format 60 years ago, and would they be compatible with current machines? Maybe I made this harder than it is.