How does it sound? inquiring minds want to know. LOL
If I were to test with the radio and antenna, I would have to wait to see how I move forward with the radio. I'm currently evaluating options for rebuilding, tuning, etc. I have a brother who is an automotive audio engineering specialist, focusing on this area for over 25 years, so I probably have more options than most.
However, in order to test the quality of the speaker, the engineer in me says that I need a controlled environment, and the test equipment needs to be a factor of 10 better than the device being tested. Testing the speaker with a 50 year old radio that has not been gone through will reflect problems with the radio and not provide a good indication of the capability of the speaker. A rebuilt 50 year old radio may not, either. I also don't want to limit the test by connecting to an AM signal with a low signal to noise ratio.
So I'll probably connect the speaker to a modern digital device and play back from a digital sound file, avoiding SNR issues with AM signals, and questionable aged analog electronics.
I am testing everything I can before it goes in. Changing out a speaker after everything is back in place is not on my list of things to do for fun.
The bottom line is that the jury is still out, but I'll update the post once I can report back on the quality of the speaker re-coning service.