No Gun Fax - and I hope there never is... The last thing we need is more Federal $(@)#(.
I do ask for pics and serial number, and I do call the manf for a "born on date" from time to time. Depends on the investment though - north of $500 and I do the research.
F2F and if they won't let you break the gun down, then walk away. Most people are on the up-and-up - at least that has been my experience. I've gotten some great deals from folks that I thought were way in my favor, but I'm guessing they thought the same.
One man's trash is another man's treasure...
If it is stolen, that's unfortunately the chance you take w/the used market.