Try your local £ shop. They usually have scrapers of some sort.
You'll need to handle them with care, though.
I bought this Stanley scraper in my local hardware store. Takes standard Stanley knife blades available anywhere. OK. It's a bit small, but it's better than no scraper at all!
The one below it is also by Stanley. I've never seen one, but you might be lucky and find it in a "proper" hardware store (If you can find one. They're thin on the ground these days.)