You can still change Scottish bank notes in the Philippines. I know this as granny sent some recently and we managed to change them at the money changer. The exchange rate might be 10 to 20% lower than the English pound
The problem is I didn't usually have the time to go searching for a money changer that would accept them, nowhere I tried even wanted to make an offer Anyway I'm exiled in England these days, so I don't have that problem anymore, now I just have to filter them to get rid of the torn ones and the ones that have been written on excessively and the really badly worn ones, if you take shiny crisp new ones they never complain.
I was in Boracay and was surprised how sharp the money changers were there, with the Manx currency. There's loads of them there as you will know. But I did manage to get some Manx currency changed eventually, at the regular pound sterling rate. Persistence paid off.