Beautiful Raleigh ! Looks like a Superbe that lost it's rear rack, given the dyno hub and locking fork.

OA will eat up any galvanized or zinc plating in a heartbeat. It can damage alloy as well. It is intended for painted or chromed steel parts.
You need to use a very dilute solution and wash with clear water afterward, followed by some oil or wax, or Boeshiled, it will rust again.

This link may be helpful regarding the replacement key.
http://oldroadsforums.com/index.php?topic=107.0



PS- Welcome to C&V !