Hi Yog.
I would say that Bearded Theory is probably your best option, date wise. I've not been yet but I know lots of people who love it and I'm planning on going 2027 as it's the Glasto fallow year. They always have a good mid-level varied line up and next year's looks decent enough. It's very popular with those who've been and has a good reputation for a community festival vibe.
If you can wait til September to celebrate that 60th, then Mucky Weekender would be the perfect place for a distinguished festival party veteran like yourself! 🙂