As you stated, i need to touch the leads with my counter's probe to check the frequency of the crystal.
In the picture you see the counter, but not the other watch.
Only the speedy trim can check the speed of the watch without opening it.
And Howard, this is how i tune my watches:
First i set it to the right frequency with my counter.
After a couple of weeks i check how much it has gained or lost and then i tune it again.
Now it should keep time within a couple seconds a year. BUT ONLY AT A STEADY TEMPERATURE.
If the MK IV is NOT temperature compensated it will most likely also gain or lose time when its heated or cooled down. ( correct me if i am wrong )
So you tune both to an average temperature.
If both watches ( the MK IV and say a P3 ) are kept in the same enviroment, the P3 module can keep better time because it is analog tuned with a trimmer ( asuming the trimmer is in good condition ) you can infinite tune a trimmer, and a MK IV "only" in 4 seconds a year steps.
Rgds
Hans ( who has probably the most accurate P3 in the world at an average temperature of 20°C )