jesus no just no. No sweet Jesus. Jesus says no. The cost of re-milling and finishing a frame is high. very few “Smiths” can do such machine work. Bad idea. The gun will also be worth less once it’s dick’ed up in such a manner. Im sure Allegheny will take your $$ and do excellent work…there are excellent surgeons who could swap out my manhood but I still don’t want their services.
OK so you want a vertec style flat back strap? just acquire a pizza gun that has the straight back strap. These include the 92 vertec, M9A3 and 92X. But are your hands that small to need a vertec? My 5’2“ wife shoots my M9A1 without any issue. spend the $$ on ammo and training, or if needed just trade it towards a vertec type model as I’ve listed above.