For the record you do not need a manufacurers license to make a firearm. It is perfectly legal to make a firearm for your personal use.
Please see
http://www.atf.gov/firearms/faq/faq2.htm#a7 (A7) Does the GCA prohibit anyone from making a handgun, shotgun or rifle? [Back]
With certain exceptions a firearm may be made by a nonlicensee provided it is not for sale and the maker is not prohibited from possessing firearms.
However, a person is prohibited from making a semiautomatic assault weapon or assembling a nonsporting semiautomatic rifle or nonsporting shotgun from
imported parts. In addition, the making of an NFA firearm requires a tax payment and approval by ATF. An application to make a machinegun will not be
approved unless documentation is submitted showing that the firearm is being made for a federal or state agency. [18 U. S. C. 922( o), (r), (v), and 923, 27 CFR 178.39, 178.40, 178.41 and 179.105]
Maggot may be restricted by California from doing it however. But no federal license is required.
This information appears also in the very front of DeHaas' book