They will still sit-in too far even with a 10mm spacer due to them only being 7j compared to the standard wheels 8j width! If your going to add a spacer of that thickness which is a bodge imo then you will need longer wheel studs all round also!
I think 15" x 7" wheels will look terrible on an Escort bearing in mind the originals are 16" x 8" all imo of course!