I can help you out here.I guess being a packrat and not throwing things away comes in handy every so often!
I replaced that entire panel with one from a car 1 or 2 years newer than my 74 as the mounts for the fan switch were broke off.The newer one had the info printed on the panel,rather than a additional tab piece(the one you want)
It's partway cracked at the 4:00 position but the lettering is perfect.
PM me with address info and I'll get it to you