Hi,
59 so another 6 years an operator can use you. Nothing wrong with that. There are enough job hoppers who leave after 2-3 years so 6 years is not bad.
I don't see a reason why they wouldn't hire you. Definitely as a co-pilot (since you're new on the 139) and depends on circumstances if you would get upgraded to command.
There's a shortage in type rated and experienced pilots so that works in your favor.
however if the choice will be a 25 year old or you, then most likely they will go for the younger pilot.
And if you're lucky, by the time you turn 65, EASA has increased the age limit........we can only hope....