First, sorry, I used to have an FFL 10 plus years ago and between my full time job and other "hobbies" the part time business never worked out. I eventually just never renewed the FFL when it expired.
Honestly If I had the FFL I probably would not have show all the details of the process
So no I cannot checker anyones frames, I do a few "slide" jobs from time to time. Installing sights or doing lightening cuts but no frames.....
One thing I should add is by all means, before cutting on a frame get a piece of flat stock, something close to the frame thickness, I just used a scrap piece of aluminum...
And practice doing some cuts... try different angles, try different style cutters, I did a lot of cool looking stuff with different ball nosed mills but when it came down to doing my guns I settled with good old fashioned checkering.