Another annoying thing to consider is that a lot of the early germanium transistors came unmarked.
At the time I think the manufacturers just assumed there were only going to be a few devices made of so few available transistors.
They turned them out, packaged them together with the part number written on the bag, and left the individual devices unmarked because it was extra work.
I suppose most of the old devices are collector-type items like Harald said, it just annoys me that I have so many of them saved from the 'old days', and
they are without individual part numbers stamped on them. Once in a while somebody will dig-up an old hobby schematic and ask me if I know where
they can get the early transistors. I probably have what they need, but don't want to spend my 'extra time' running them through a curve tracer to ID them.
There were so few early germanium transistors made, that a lot of hobby circuits were generated that could use any one of the three or four of the closest matches, and
still work. I have old bags of Olsen Electronics germanium transistors that will generically say 'Equivalent to', and then list 4 or 5 transistor part numbers, with no part
numbers stamped on the individual transistors.
One other thing: Some of those early transistors were made FOR some specific use by a radio manufacturer. So the transistor manufacturer would stamp the transistor with an identifier for the
radio manfacturer's use only during assembly. Like 'A1' or '4', or something that the radio manufacturer
used to ID the part for their assemblers. That identifier is useless to anybody except the guy who put
the radio assembly together.