Not exactly a one off for personal use, when you buy $10,000 worth of parts to make weapons without serial numbers for fun and profit. I wish him luck. Anybody else, I recommend familiarity with the law, before going into production. With no crimininal history, I hope he gets out of this time, with a better understanding of the do's and don'ts of his new hobby.
In the oral arguments for Cargill a couple weeks ago, the Supreme Court was very interested in the ATF's plans for enforcement of the bump stock ban and they weren't too happy when the ATF answered openly and on the record, they believe they can charge anyone who had a bump stock one day after their order made them NFA items, even in districts where the appellate courts said the ban was unconstitutional. The Court asked them about how people would know, even joking about gun owners sitting down in the evening with their coffee reading the Federal Register.
If the ban is eventually ruled constitutional, they are most likely planning on going after everyone. Thus, I think it would be an error to think that the ATF or the Federal prosecutor would agree to or ask for leniency. This is exactly the guy they want to make an example of. If they're willing to put this guy away for a long time, everyone else better imagine what the ATF will do to them for something similar.
The ATF is on an all-out war with gun owners. In general, and because of the abuses of the ATF and all branches or departments of the Executive Branch during and after the Trump administration, I've been saying that every Federal Government supervisor and above, within 500 miles of Washington DC, regardless of department, needs to be fired to clean house of insurrectionists and those who participated in the coups against Donald Trump.
For the ATF, though, it needs to be every single person fired. Let them reapply for non-supervisory jobs (no existing ATF personnel should ever be allowed to be in a supervisory role in any law enforcement agency) but to get or keep jobs they should pass a lie detector test that, even under orders, they never knowingly violated the constitutional rights of any person.