Here's a useful discussion about this, including a pic of the replacement panel...
https://www.volvoforums.org.uk/showt...e+repair+panel
Stephen - I'm not saying your repairman isn't very good - but I would suggest using the replacement panel. Making a 240 tailgate fit is hard at the best of times, but making the tailgate fit with a hand-fabricated sill beneath it sounds like a nightmare. It's a deceptively complex curve with a shoulder that the chrome trim goes on.
My two-bobs-worth,
John