My ORIGINAL license is tucked in my A&D book, two unsigned paper copies in my wallet (targets of opportunity when traveling) and I have a signed SCANNED copy in my computer. Have done business at long distance with folks by emailing them the scanned copy. Yes, ATF says that an electronic copy- faxed or emailed is OK- as long as it is legible. Some folks want a paper copy, but regs do not require a paper copy.
Just to show you what you get in to with a C&R, got email from a member here on New Years Eve- he knew I collected older Mossberg 22s, and had run across a nice Mossberg 51 at a dealer in Maine (I'm in VA) Called the dealer New Years day- they were open, described the rifle, we agreed on price, yes, they would ship, yes, C&R was acceptable. Gave them CC number, emailed them my C&R. Jan 4th mailman brings me my rifle.
For $90 and $22 shipping, I was pretty happy.