Reeni, when I bought some 15" rims last year from Compomotive in the Uk they would not supply without a measurement form being completed. Then the onus was on me if they did not fit.
 
I think you are lucky if the supplier will swap them over for you.
Its not just the width obviously, its how much they stick out the from and the back.
Given our cars are so old, and have a history,  nowone  can be sure the correct or original struts,diffs,brakes etc are the ones shipped out by Ford, so you really should do some measuring if you can.
 
Heres the measurements I came out with for 15x8 and 15x9 wheels I needed, just to give you an example.
This was for the escort van with bubble arches, so they are a deep dish wheel, not the same as what the Capri needs so dont use those measurements.
Good luck

Thanks deano
Those guys must be different to most others in the industry.
There was no problem in changing over to another rim and size.
They even organised freight for the return of the 5 rims.
In which case special thanks to the guys at Canterbury tyres and mags Melbourne.

gtv6capri
If you want 15" but stil look old school have a look at these https://www.custommustang....5-bp-3.75-bs-machined

This information had been sent to me on this rim
Do you think there likely to fit ?