Window delaminating - what adhesive?

[EcclesAsh]

My front caravan window is separating/delaminating and I need some adhesive to DIY repair.
I was going to use Bondrite S1220 but it's out of stock.
Has anyone had any success with a different product?

 

[EcclesAsh]

For future reference, I have been in contact with Trade Grade Products Ltd (The Glue People) and they were very helpful and recommended Tremco SPO30, so I've placed an order at £11.22. I'll let you know how it goes!