Well in jfk case that would have been a tough open casket
Yes, true, but before JFK's death, there was no official protocol in how to deal with a current or former President's funeral.
The Reagan family is following the protocol set after JFK's death.
And to add, it will be laughable and sad, IMO, to watch a Military Honor Guard bringing in Clinton's casket, for he will be ever known as the President who "loathed the military".