The exhibition vinyl works ok but the edges were a bit inconsistent, which could very easily be attributed to my skill or lack thereof. 
I used 3m edgelock tape to make the border and even it did not provide 100% clean edges... not sure I could have screwed that up so it could just be the pre-painted substrate the customer provided. 
The white paint is Valspar Ultra Primer + Paint from Lowe's and White Semi-Gloss.
The green paint is Super Paint Gloss from Sherwin William's to Pantone 349 C. I tried to just get the paint from Lowe's but they didn't know how to match the color without a paint chip... despite having me provide them the exact hex, rbg, cmyk, and even the web link to color on 
http://www.pantone.com/pages/pantone/colorfinder.aspx?c_id=6742
So I gave up and called Sherwin William's, which is where I get the paint for my house anyway. He had a swatch book and the paint was ready the next morning. I'm not very impressed with the Super Paint. I used a 6" smooth poly roller and it took 4 coats to get full coverage. I was expecting much more for such an expensive brand... also there is hardly any gloss on the green. 
I am having a hard time getting the Oracal 751 white vinyl to stick to the green and I'm afraid it will peel shortly after I hand it back to the client. I plan to give it a good spray of clear acrylic but that isn't going to make it adhere any better to the paint. 
Details for Each Photos
- 1/2" Plywood substrate provided by client to match existing sign
 
- initial masking using Oracal exhibition vinyl for paint mask & 3m edge lock tape
 
- close-up
 
- detail of bottom left edge
 
- detail of center left contour
 
- 1st coat of SW Super Paint Gloss - Pantone 349 C
 
- 2nd coat (2.25hrs later, ambient temp 68f)
 
- 3rd coat (next morning)
 
- after 4th and final coat to try and remove roller marks, removed border tape
 
- after removing oracal exhibition vinyl
 
The current state of the 
sign is that I have placed the phone number on the bottom and I'm trying to let it adhere to the green paint. If it doesn't, I will just use paint mask and do those in the white super-paint that the client provided.
Thanks for ALL of the excellent help so far from everyone. I want this 
sign to be as gorgeous as possible. I don't have a photo of the current 
sign but I will try to get that and add it in a future post. 
I would appreciate any suggestions or tips on getting the vinyl to stick to the green paint. Otherwise I will do paint masks for those and just use the white paint which I also have on hand.