People i have been reading threads all day of user misinforming you guys on the proper way to make an sbr. You do not and i repeat you do not have to engrave your lower with any new identifying marks or serial numbers or the ridiculous long name of your trust to be legal. The only time you have to engrave your lower is 1 if you plan on selling it or 2 you actually made the lower yourself as in you own a cnc machine and made it from a blank piece of metal. The original manufacturers name and serial number is more than suffice for the atf. When you fill out your form 1 just use the serial number on your lower. If you do a form 4 theres no reason at all you should even be asking this question. The only difference in a form 1 and form 4 is the form 4 has already been done all you are doing is taking ownership. The form 1 is still considered a long gun so you will be making it into a sbr so thats why you will need the form 1 then after that the new owners takes it on a form 4 but ahhhh ha you have to engrave it before you sell it. I hope this helps anyone wanting to get into the wonderful life of sbr's its not as hard as people make it out to be. And yes i have the letter from the atf stating all this and with 13 new pending stamps just this year alone i think i know what im talking about. Remember the 4 rules of shooting and happy shooting my friends