Dave,
Here is what I've done in the past when building DD kits for people. I start with a complete center console, the whole 9-yards (~8.25m)
and assemble everything so the gaps are all the same as they would be in the car. This is tricky since it's not actually bolted to a metal trans tunnel but it's doable. Then take some winter sealing window shrink wrap and wrap everything nice and tight. Take a hair dryer and hit it to tighten up the corners and make it all so it's nice and smooth. Then take some release fiberglass agent and coat it evenly. I don't remember which brand we had the best luck with but if you can't find one that doesn't interact with the window wrap, you can get away without it, you'll just have to clean up the back side of the mold you'll be making. Then cover the console with fiberglass mat. I used chopped up mat and glass stir sticks to get in the grooves. You're not trying to get in deep, just enough so you have the raised bump between the parts of the ashtray cover, cigar lighter trim and airbag light panel and the radio surround. Once that cures, carefully remove the fiberglass mold you just made and take all the silver parts and remove everything you can from the back of them. Then place them in the mold you just made and bond them together so you have the lower portion as once piece to graft the switch panel into. I can't really describe in words what you will need to do for that but you'll be doing a lot of trial and error to fit it all together and make it look like it belongs that way. The radio surround is pretty straight forward. Cut the switch group from the one you plan on using and graft the top of of the second radio surround to the part you removed. Leave the perimeter of the radio surround intact, only trimming about an 1/8" (~3mm) into it from the inside edge. Then after everything is glued, bonded and cleaned up, hit the entire console with some paint and install the radio of your choice.
Take care and I hope this helps you out a little. You've helped out many people on this forum so you deserve some as well.