I just received my FAA 333 Exemption recently and now I'm ready to register my drone. I have my N number reserved already and received a confirmation in the mail recently. I am awaiting the 8050-1 forms from my local FSDO and had a question regarding the 8050-88. I purchased my drone directly from DJI and the only documentation I have from them is my online receipt. Will this be good enough when sending the information to register my drone or do I have to get some kind of signed bill of sale from them? They don't even have a PDF version of the receipt. It's basically printing out the webpage. The packing slip that came with my drone doesn't have much info either. TIA!