If I get the 07, at what point do I pay the SOT? Upon issuance, upon the first sale, upon the first manufacture, at my leisure, upon approval of the SOT registration, etc.? When do I pay?
2) Also, can a type 07 engage in gunsmithing?
You don't have to pay a SOT unless you want to. The SOT payment is to be made before June 1st and it goes until June 1st. I actually payed my first SOT in October and had to pay again in May so I lost 5 months of it. The SOT is what gives you the ability to buy,sell, or make NFA stuff.
The 07 Is classified as a Manufacturer. You can do anything that a gunsmith does or more. As an 07 you could make a receiver from scratch, give it a serial number and register it with a Form 2. Same with a suppressor.
The 07 is only 150 for 3 years so its actually cheaper. It was supposed to be the other way around but the ATF screwed that up and its been too long to worry about it.
The SOT is only voluntary. It covers only NFA stuff and is 500$ a year for most people. Make over 500,000 a year and it jumps to 1000$ a year.