test it online and see what it works one- either way you best to keep it to what was in the deal incase if messeed up and you left sorting with currys - which when sorted the M4 will be out.
on my gift card it just say valid for macbook, no mention of macbook air or colour of SKU
thats what they do when the book the GC- so it needs to be exact model
by sku do you mean the exact model like color? so if i say grey, that gc only valid for grey or any macbook air?
I have done the same. Trade-in plus price match amazon plus 7% employer discount on outstanding balance. I have sold my old huawei laptop and got new macbook for additional 350. Amazing deal!