but I always sent my watches to the RSC via my local dealer. They serviced my 1675/8 with a modern daytona leather strap and buckle on it, I've always been advised as long as its genuine Rolex they are fine. Maybe its because I go through the dealer, who knows.
What led you to beleive it was serviced by a RSC, is there any paperwork with it.
Most the fun of the hobby is doing the investigation and ground work, sometimes it leads to a very pleasant surprise, but its not unknown to lead to a little heartache.