PTL I was successful in removing the seat! Thanks to "Wonder-Dog" chewing all the upholstery & foam I was able to find the two rivets holding the base of the seat to the lock latch, drill and grind the rivets off, and lift the 'carcass' from the bike. Since this R3 was abandoned then stored in a shop for years, all the stuff under the seat hasn't seen the light of day in over a decade. The tool kit case and the tools inside are all present as is the owners manual and maintenance book. I haven't looked through these yet but, because they've been stored in a plastic pouch, they seem to be in good condition. I am grateful for your suggestions, PH, and that of the others who took the time to write. Once I get the proper blanks for the lock from a Triumph dealer I will be heading over to a locksmith for key-work.