Sounds like your man has merely opened the chokes from the original 37 & 44 thou to 30 and 40 thou.
Thats a fairly basic procedure but 'regulation' is an entirely different ballgame where you are looking at the percentage of the shot load in a 30" circle at say 30 yards, or whatever you decide, using a specific cartridge, shot size etc. As a rule of thumb 3/4 choke should equate to 65% (shot within the 30" circle) and Full choke 70% within the circle.
Honing the chokes to 3/4 & full may (or may not) give these rsults with your gun & chosen cartridge, its very much a trial and error job. I doubt if anyone is lucky enough to get these things bang on.
I am sure someone will come along to explain this better than I.