ey aren't cheap. They are made for microwave mixers and detectors
I suppose the 1N271 is obsolete, as well? Microdyne had switched to them fr om earlier pat numbers in the late 1990s.
There are Ebay listings for 1N34 diodes. I had a pound of them, from Poly-P aks, but an animal dug a hole under the wall into my shed, and used them to make a nest. Needless to say, the several thousand diodes had their leads rusted away. I still have some that were salvaged from some '70s era comput er PC boards. They were daughter boards with individual flip flops, and the y had silver mica capacitors. I can't imagine the price of something like t hat, back then.
Another trick is to DC bias a diode to give it closer to a zero volt forwar d drop. This was done in some radios in the early days to improve sensitivi ty. I had to scratch my head the first time I saw that trick, with a 6H6 du al diode vaccum tube.