I don't have enough knowledge about Scottish law. I believe you have your own law.
My ex- husband was getting an additional pension for me which is called wife's allowance. As I remembered it right, his claimed started when I was still in the Phils. and I am not an ILR holder. I think is worth trying Arthur before it's too late. Try to go DWP and ask about it. Come to think of it, it's not your wife's claim but your claim.