They did not require anything to be added, but then again, they never saw it. I just had to supply a photo of the engine number. I don't think you have to add anything that wasn't required when it was manufactured, but I did read where all motorcycles are required to have 1 rear view mirror and a brake light.
On a side note, I'm taking the 53 to the AMCA national meet in Rhinebeck, NY on June 9th.