In pre-Mojave days I got a lot of use out of the free RB App Checker Lite:
https://brockerhoff.net/RB/AppCheckerLite/
Is there a similar all-in-one utility that can checkcode signing and notarization simply by dropping an app or applet on it?
I think Howard Oakley might have one. But probably the best test is to email it to yourself, and then try the received copy.