Good questions, thanks! I'm happy to go into more detail and I'll get some in progress pics as I continue to make more.
These are two completely separate and distinct processes. I started out several years ago just trying to solve the glove box door issue, then onto the gauge surround, and one thing led to another and I wound up doing all the dash pieces. I only started thinking about woodgraining a couple of weeks ago. To make the set above, 5 of the 6 pieces were test pieces I cast years ago, the gauge surround was the only one I had to make fresh.
I was thinking about ordering the woodgraining stuff piecemeal but once I started adding up all I needed just to get stated it made sense to bite the bullet and get a kit. I got their midrange set that came with one 6" roller and one large pattern stamping sheet. Its a bit pricy but given I can make multiple sets of plastic it made sense to me\for me.
For the mold making, here's a good video of a Smooth-On guy making a parking light lens. The overall shape of that lens is a pretty good analog for the dash end pieces.
I'll go into more detail and will add some more pics, but theres a certain football game on TV today that needs to be watched!
How To Make a Replacement Car Lens Using Crystal Clear 202 (smooth-on.com)