It is the trackday organiser who will want to see your licence to prove you are legally entitled to ride a motorcycle.
I normally just show my plastic 'credit card' part - never get asked for the paper one (the one with endorsements on!)
I would seek assurances from NL that they will accept a photocopy (and get persons name who said it would be OK) or else could be a wasted day
Entry Forms? Check
Warmers? Check
Dogtags? Check
Transponder? Check
Talent? ....er