There's nothing non-GMC about the dashboard.
Is the seller calling it a Chevy or a GMC? Does he have it titled as a Chevy or GMC? The only Chevy thing about it I see is the engine - and engines got swapped often...
There are a lot of hodge-podge trucks out there put together with parts from other trucks. Lots of interchangeability over several years within that series.
You should verify that the VIN/ Serial Number on the truck and on the Title match.
