I'd get a quote from a local canvas shop. It doesn't need to be marine vinyl. You could get away with sunbrella. Ask if the material choice makes a difference in price.
Sunbrella material and someone who can sew would be very, very inexpensive. My wife made sunbrella covers for the Honda 2K generator and the outboard motor. A couple of yards of sunbrella to match the canvas and a few hours in the sewing room.
I'm going to talk to a local canvas shop. I want one that is like a factory cover for the dash but also a extra throw sewed to it that covers in front of the dash. I had one made before as just the extra that had a snap around the window support and I think the guy charged me $60. I'm sure he could make me a cover with that for $175 and no shipping with snaps. Of course I will be getting some of my camper top remade too.