comparing the different crystal oscillators

 I dug out the red counter

red counter upper left

and the W1FB crystal test board from Jan. 1990 QST, page 21

W1FB board upper left

as well as the Butler grounded base oscillator still on the 3M breadboard

 (see the previous blog: https://wb9kzy.blogspot.com/2022/07/series-resonant-crystal-oscillator.html ) 

for a comparison.  All measurements were made with the clear top ebay counter.  The "red counter" was just used for the crystal oscillator.  The W1FB board is from FAR Circuits, only the oscillator part was built.

The measurements were all made after a 30 second minimum "soak", the counter had been allowed to run for at least an hour.  I closed the window to make sure that there weren't any breeze effects.  The room temperature was 75F.

only the last three digits of the frequency were entered

And I don't see any perfect correlations, even between running the Butler oscillator in two different sessions.  

It may be time to try the G3UUR crystal test fixture and/or try using the NanoVNA to measure the crystals.

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm