These doors in essence are in good condition. Indeed the french doors are handmade from Burmease Teak -probably the most robust of all timbers but alas no longer available and actually illegal to import into the uk.
These are about 30 years old. So the beading has come away from the rebate and the rain is doing its job filling the rebate with moisture, left as is wet rot and a new door would be the only option. I had to wait for the weather to be dry for at least 5 days in a row.
I needed two days to do the job and at least 3 days of dry weather prior to that so that the rebates were at least dry enough for the sealant to adhere to. It’s laborious.180 mitre joints had to be cut and fitted but worth it and economically viable as replacement doors would have cost considerably more.
There is the environmental argument as well a lot less resources are used. The customer then followed on from me staining them to match the doors.