That's a mega find!! For a collector or retailer it would be already amazing, but the fact it links to your grandfather for me is the reason to keep them all personally and start making your own story with them basically as new watches.

The NOS Autavias will be worth very strong money, as will the Monaco in that although it had gasket melt it is still NOS.

The quartz ones are not worth anywhere near the same amount, partially because they don't have the heritage and design of the others, but still great to have in a collection in my opinion.

Everyone is a bit different but for me I buy my watches to be worn and enjoyed, and the thought of being able to wear watches which are 30-50 years old, straight out of the box and linked to a family member would make me keep them.....but then that's said as someone who truly loves the Heuer brand. The vibrancy of those 15630 hands is epic 😍😍

If you're keeping them then get them serviced as soon as possible, and if not then sell them as is and let the new owner decide. I'd suspect some buyers would actually prefer that, and pay for them being untouched.