I have no issue with sending a photo ID if that makes the FFL feel comfortable. But as Dave K has stated I see no benefit from it.
Mark my word, some uniformed FFL holder is going to start asking for SS#'s before long and this converation will appear again. IMO you never give the government more information than is required. And by the way, my FFL does transfers for me for no charge. Just one of the benefits of a 30 year relationship.

Dodging lions and wasting time.....