I my opinion, using NOS caps is a dice roll. After a certain number of years, even on the shelf, caps can and do dry out.
Here is something worth discussing...
If you are trying to get the best vintage tone possible and are fortunate enough to know someone with a really great sounding vintage amp, is it possible that one could measure each part...and by using those drifted values (common in old amps) in a new build, get closer to a vintage tone
as opposed to going the NOS path from the beginning?
Could this get you in the ball park of the tone of a vintage amp - but with all new parts? (not talking about the further impact of NOS transformers or tubes)
After all...most old amps sound great because of how the parts have drifted...or settled in opver time.
Just my 2 cents.