Mine is stored up on a shelf so can't verify but the plastic buttons you are talking about are pins that were melted flat, right? No way to reuse that style that I could imagine.
Still assuming it's that style, I would see about taking a Dremel to the head to remove it, then see if it's big enough to drill and tap. If so you could bolt it on with flat washers. If that doesn't work you could see about epoxying your own head on it. The benefit being that you could do the same grinding to remove it if needed in the future. Or you could always go the adhesive route and forego the pins altogether
Flying blind so disregard if the 'buttons' aren't what I am thinking of
Scott
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Camano' 1986 F250 Supercab XLT Lariat 460/C6
'Chanute' 1980 F350 C&C 400/NP 435 - Gin Pole
But there ain't nothin' wrong with the radio