I've read your "JB paste" thread. JB doesn't accomplish much on steel... at least not in anything you'd call a reasonable amount of time.
You'd be better off with "very fine" lapping compound (600-800 or finer grit)... and like you've guessed and been told by Sam, it's a pretty terrible idea. This previous sentence is more a joke than an actual suggestion.
Have you disassembled the gun and looked at the transfer bar, trigger, sear, hammer, spring and their pivot points and contact surfaces?
I realize you don't want to tackle this yourself, but just curious if you've looked at, cleaned and properly lubricated those parts.
The design of the Mak ignition system relies on a pretty stout mainspring weight (5200 grams is the rated DA
pull weight... or 11.5 lbs)... plus, the leverage with the DA trigger pull is only adequate.
You can, by polishing
only and proper lubrication make the DA pull
smoother on the break... but making it lighter with the existing parts without skirting the edges of reliability is tougher.
A bit of sear and hook "optimization" will make the break a bit shorter and crisper, but if you're happy with the SA (5 lbs) trigger pull, then there's not much point to it.
I know of no professional 'smith in the area who has good Mak experience... or (an unethical) one that wouldn't take the job, then charge you $50 an hour to experiment on your gun for 3-4 hours. Sorry. Good luck.
C