That isn’t the wild west. In Utah the guns have serial numbers, waiting periods, background checks, and one handgun-per-month purchase limits.
California is the wild west. In California the gun laws are so restrictive the real waiting period is however long it takes you to complete the machining on the 80% blank. There currently aren’t any background checks for ghost guns, nor purchase limits. Even red flag laws don’t include ghost guns although that is soon to change. There typically aren’t any serial numbers on ghost guns.
It is California law that you have register ghost guns and get a serial number from the California government which is then supposed to be put on the ghost gun. So called “assault weapons” also have to be registered with the state per the law. Of the estimated M-M-Millions of ghost guns and assault weapons in California, by the legal deadline to register only 6,213 owners had registered a total of 13,519 guns.
I know that ghost gun kits can be purchased in Utah and that some enthusiasts do so, but in California the number of no-serial number ghost guns is crazy. Last year 41% of guns seized by law enforcement in Southern California were ghost guns.
Although they are cracking down on it now, there were machine shops that rented time on CNC machines preprogrammed with tool path code and an aluminum block secured to the working table. It was of course your choice to push the ‘go’ button to make whatever the previous person made with their aluminum block before they accidently left the code in the machine. Afterwards there were build parties to attach interesting off-the-shelf bits and pieces to whatever you decided to make on the CNC machine.