I found some discussion on F-chat about these switches. First, I got some Fiat X1/9 switches (the one with the white button). I was told the Fiat used the same switches. This was wrong -- the Fiat switches have a button that is too short and a mounting ear with a hole. They are meant to be secured with a screw. The original ones just clip in. I dug deeper and found a part number and a vendor. Apparently the Porsche 356 uses the same switch as the 308.
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Ok, these aren't EXACTLY the same either. The replacements have a black button and the rear connection is not the same. However, I think they're close enough to work. This is a busy weekend, but I'm hoping to have a few minutes to see if these switches will work.
Also arrived today is a box of black anodized pop rivets for the engine cover. These secure the louvers on the the rear hatch. I think I only need about a dozen of them, but the smallest box I could find was 250. There are way more than I'll ever use so I'll see if any fellow F-Chatters need some black pop rivets. Better to give them away to someone who can use them than to get lost in my shop.