A dial we've only seen once before, it helps validate that earlier dial and actually carries the correct handset too. Finding a case in the correct serial range will not be the work of a moment but they do exist and then the owner will have a watch that should attract the same sort of premium as any other Chronomatic-dialled Heuer. Except this one is still rarer than those.
I hope we don't see it with later case and mismatched hands at some point - if the new owner is reading and needs any advice on serial range etc, I'd be happy to help. I'd like to see it stay as original as possible.
As to worth it, that's for the individual to decide but the movement is probably worth that on its own, so you can say the buyer got a Chronomatic dial for free. Though it looks like there are some replacement parts in there.