Just bought a SilencerCo Saker 762 through US Defense Solutions. They had to order it from SilencerCo as they did not have one in stock. The salesman said he would let me know the serial number as soon as he had that info so I could start my Form 4(I just got a trust started, 1st NFA item). Is it OK for me to start my eForm using the serial number even if the dealer hasn't even physically received the can yet? Thanks in advance.