I've always found this subject difficult cos there are so many different shaped back sides out there. Some like the stock, some don't. Some like the Corbin, some don't. Some like the gel insert, some don't.
Now if we were all the same, then we might have some more constants out there to help someone who asks this question but we aren't so in that case, I reckon go and see a well known and respected upholsterer who has done good work for others and get it done that way.
