Possibly.
You could try them reverse biased on a high voltage supply with resistor current limiting and see what voltage they break down at. Also try them on a square wave generator in some high speed switching test and compare to a 4148.
If I had those I would say that if you can not be 100% sure then they should probably not be used for major builds as you will never know for sure and the design may fail in unexpected ways when replicated with other parts.
You could try them reverse biased on a high voltage supply with resistor current limiting and see what voltage they break down at. Also try them on a square wave generator in some high speed switching test and compare to a 4148.
If I had those I would say that if you can not be 100% sure then they should probably not be used for major builds as you will never know for sure and the design may fail in unexpected ways when replicated with other parts.
I couldn't find any 4148s to compare these to, but I pulled some 1N914s from a donor board to test against. My yellow-banded diodes begin to break down closer to 75V...a bit lower than the 914/4148. At first glance this seems more consistent with a 4151.