Check with Long Rifles Inc. He may be custom inletting flat top stocks by CNC. If he can, you should be able to find a stock at Mcmillan or Manners and be in business. I don't know if you have decided on bottom metal, but it is also sort of an issue. PT&G may be a source or MWG as the options...
Try Midwest gun works. I think they had some Mcmillans left over for FN M70's. Don't fool with the Hogue stocks as they are not what you want. They are just a stop gap. Good luck!
L3 Rifles LLC in Augusta, Ga. Jon Slagle. Learned his trade from the best gunsmith in the country. His work will not disappoint and his guns absolutely hammer.
I tried the PTG route over 6 years ago to no avail. It is some of Dave Kiff's rainbow stew and snake oil to slip$$$$ out of our hands. This follows along the line of his other products and marketing techniques. Save your money and time for better products.
If you like it buy it. Somebody is always kicking something they have never owned. Armchair experts are fools looking for an audience. Find yourself a good smith, get a premium barrel and let him do his magic.
Jon Slagle, L3 Rifles in Augusta, GA. The last smith at Gradous Rifles under Roberts tutelage for 3 years. He builds hammers as he learned the art from the best.