If looking for an original production installed type map light, save your lunch money! They do show up occasionally and some that are less than pristine can be held for a reasonable price. New or used in very good condition pricing can reach insane levels. If not worried about being Concours correct than I would look at a lamp a fellow forum member Paul (Rocket 366) manufactured. 73 Pony tested a prototype for Paul and I believe was quite pleased. You could probably contact Paul or 73 Pony with any questions if you feel this is something you might be interested in. I have also included a link to the post about the lamp.
https://www.7173mustangs.com/thread-center-console-map-light--28072?highlight=map+light
