I was thinking about pinstripe as well you mean the stick on stuff. Just not sure how it will hold up in the Oz heat. When I get home I will measure the original chrome. I'm thinking of heat sealing the chrome from the rear of vinyl to the window chrome. See how it works. I've got some cheap vinyl on the way through eBay so I'm just going to play around. If the pinstripe did unstick it could be reapplied with new stuff cheaply. I reckon trial and error but as long as I don't ruin the metal top plate then nothing ventured nothing gained. Be tuff showing the mates my sewing techniques.

Still reckon though pop rivet from the back to the chrome or pinstripe will assist. And I'd use an iron from the rear if I go window chrome.

If you sort out the chrome, you could cut the patterned D shaped insert out of a stuffed trim and attach it to the new board, then put the new plain vinyl around the outside of the D, pait the lot with vinyl spray and attch the chrome which would cover the join edge

Not a bad idea JR. But want to be able to do 4 cars so a mixture of brown blue and red won't work. Although I know you are suggesting vinyl spray. I had thought off laser cutting the pattern from 3mm Mdf and using Teflon fabric and a heat source iron with attachment/ soldering iron etc just running along the template. Will just try things out. The Center pattern however is normally in good nick so will consider your idea if all else fails.