You're right, I wasn't paying attention to the start date of the F-50R.I'm not sure how many, if any, rosewood back/sides Guilds were made in the '50's. Most were maple, transitioning to mahogany.
Does anyone know what kind of rosewood was used on Guild guitars in the 50s? Was it Dalbergia nigra (Brazilian rosewood) or some other kind? If braz it would mean CITES certificates are necessary when passing borders.