In the province of British Columbia you used to have to write for a “C ticket “ to service gas appliances.
If you wanted to become a Gas Fitter you would then write for your “B ticket”on your way to an “A ticket “.
The card in my wallet is a “Certificate of Qualification “ to preform the duties of a “ Gas Appliance Service Technician ”.
In these parts it is called a “Gas ticket” , hard to get a job in the appliance service industry around here without one.
I do not recommend “drilling out” an orifice and by using a #52 drill I assume you are working on a 10,000 btu burner or burners.
Orifices of all sizes are available for a minimal cost. If you find a source for the orifice they will probably have the regulator you need.
If the regulator in not clearly marked as convertible to N.G . There are no adjustments.
You need to buy a new one, and the proper supply hose.
1- Psi = 28 in's wc or 1-Osi = 1.75 in's wc . Do the math , get the right one.
This link might help
The manufactures conversion kit comes with the proper regulator and orifices . All the ones I have seen for BB-Q's also comes with a length of hose with a quick disconnect that fits into the N.G. outlet.
If you insist on doing it, “the hard way” , double check your calculations.