Motorcycle Repair: rear shock mounts 1981 Goldwing1100I, rear shock, bill silver

Question
 Can shock mounts be replaced or do I need to drill and install a bolt?

Answer
Did you damage the threads on the mount end? These are welded into the frame as far as I know, so would require the services of a talented machine shop to replace. Putting a bolt in place of it, would be rather risky, as it would be hard to make it secure there.
Either try to rethread the end to clean up the existing threads or perhaps reduce the outside diameter to the next closest smaller size and go SAE if the metric step is too much of a jump. Might want to check some GW sites on this, if it is commonplace.

Bill Silver