You could try a heat gun on low & try to push it back into place - but you may have to build a wood jig to form & hold it, or sell it to someone else for a nice DD quality top, & get a nice repro from 914Rubber, Stoddards, Sierra Madre, AutoAtlanta (about $370-400 last I recall) - as the originals are long NLA (although an NOS pops up every now & then for big bucks).
If yours is a DD & you don't want to pay for a new repro (which use SS instead of mild steel which rusts on the originals, by the way), you may just want to be happy that's all that is gone bad on it.
Tom
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