Hey 3L3TRIC, spray aerosol Vinyl dye is 100% the way to go. The main reason is because it doesn't add any thickness and it won't run. If you're using spray paint, you'll have to be careful that the paint wont drip and those drips will dry into an uneven surface. With the dye, there might be a slight drip when spraying but it will dry flat into the finish.
I painted my 200 a year ago with vinyl dye and the lid is a nice dark green, not lime green. Finish is more matte than gloss, very similar to the original wurlitzer plastic finish.
https://imgur.com/a/RLa3QPLFor the dye I used SEM VP-5084 "Dark midnight green metallic". If you're unhappy with duplicolor I'd recommend looking at the SEM color catalogue, they have a large selection of colors. The picture of the can makes it look like a metallic "sparkle" green but this is actually very close to the original forest green wurli colors. FWIW, I've had my wurli professionally serviced by a company that sees a lot of EPs and they couldn't tell that I had painted it. I'm very happy with how it turned out and think that this is the best way to refinish the a wurlitzer.
I also didn't use the primer, I simply just did a light tack coat to give the full coats something to adhere to and it worked fine for me.
1. I didn't sand the finish at all. Just make sure it's clean of any dust and wipe it down with a damp cloth or something and let it dry.
2. Tape off the faceplate and trim. This is the longest part but important to make sure you don't miss any of the plastic. Also so you don't get dye on the metal trim, but if you do you can scrape off carefully.
3. I just put it outside on a cardboard box and sprayed. I used 1 full can and it was cutting it close, to be safe you might want to buy a 2nd can, but you can refinish a whole wurli top with a single can. I think I did 3 full coats total.
4. Buy a respirator and spray outside or in a well ventilated area.
5. Let it sit for 24hrs and enjoy!
Good news is that if you missed a spot you can repeat the process and there shouldn't be any noticeable spots because each layer isn't adding much thickness or drying. The layers will all blend into one another.