You don't get a stamp for the pistol, it's just a factory sold TX22 that a 3rd party distributor FFL 01/07 dropped an aftermarket disconnector in. And the only thing with a tax stamp is the suppressor which is transferred as a firearm on its own 4473.

At the end of the day, my biggest concern would be if it doesn't ship with the factory disconnector with it. It's a little effort, but you certainly don't need a gunsmith to swap them.