in a hurry.
The appropriate legalese is in 27 CFR 479.102
The end product has to have the following:
- Manufacturer (that's your name or the name of your trust)
- City and state of manufacture
- The model and serial number
If you're using the original model, serial number, and gauge of the Title 1 firearm, you just need to add your name and city/state. Markings have to be .003" deep and in a typeface at least 1/16" tall, and they must be in a "conspicuous" place.