Hey Johnny D - since you are "at this stage," please know that it wasn't terribly difficult to reapply the vinyl and start to reassemble the upper dash assembly with the replacement wood veneer pieces. The advice provided in this thread was solid, so I followed it. I could not locate the 3M spray adhesive that was recommended, but found a substitute at a local NAPA auto parts store (Dupli-Color Automotive Series Spray Adhesive 9000).
After stripping off the old vinyl and filling in some holes and defects with "plastic wood," I sanded the surface & cleaned it up. I filled in the areas where the "fins" attach with a small amount of painter's tape so those areas would not collect the glue. I then sprayed on the adhesive & laid out the new vinyl to cover the surface with about an inch of margin all around. I rubbed it in thoroughly to eliminate bubbles and then clamped a couple of wood pieces to press it very flat for a couple of hours. Then it was very easy to trim away the excess with a sharp blade around the edges. For the very small detailed areas -- including cutting out the slots for the wood fins -- I used a small surgeon's scalpel (a small hobby knife will do) to get into the nooks and crannies and remove excess vinyl. Patience is truly a virtue, but this is certainly do-able. Good luck!
After stripping off the old vinyl and filling in some holes and defects with "plastic wood," I sanded the surface & cleaned it up. I filled in the areas where the "fins" attach with a small amount of painter's tape so those areas would not collect the glue. I then sprayed on the adhesive & laid out the new vinyl to cover the surface with about an inch of margin all around. I rubbed it in thoroughly to eliminate bubbles and then clamped a couple of wood pieces to press it very flat for a couple of hours. Then it was very easy to trim away the excess with a sharp blade around the edges. For the very small detailed areas -- including cutting out the slots for the wood fins -- I used a small surgeon's scalpel (a small hobby knife will do) to get into the nooks and crannies and remove excess vinyl. Patience is truly a virtue, but this is certainly do-able. Good luck!