Your old 61.75 is no longer valid, but I couldn't be issued with a new 61.75, as the old one was still in my name. Instead, I was issued with a revalidated replacement 61.75. That was when my old UK licence was replaced with a JAR number on changing my address.
You can, at a price, do it in person at the CAA, or for free, having payed the CAA to conform your details, at any FSDO. In 2010, Denver were puzzled as to the procedure.