bnice,
ASSRA has Eric Johnson's shop notes. I was able to get info on my guns ; make of gun and serial number for each barrel.  Also, when the guns were barrelled and what work was done as well as the name/address of the person the work was done for. I bought a numbered barrel several years ago that was apparently made so late it wasn't in  EJ's shop notes. It must have been one of the last ones he made. You can find out if EJ barrelled the action.
I'm still trying to find out what the star designations mean. I have a 1940 barrel with no stars, a 1952 & 1962 8star and one from 1963 marked 5star. The last one I believe is 1963, since it's not in his notes and is threaded for a Ballard.