Yarn and Fabric related

I have brought some new rear seat covers for dolly a burgundy colour which ended up been a little reddy I had ordered new cushions cover which where more purple so I didn't have enough wool to make a whole cover so I just made the fronts and because if I can get away with it and don't have to sew I will I added buttons to fix it on I havent got the inside bit so I not sure if the sides will gape at sides if it does will have to rethink.