Dano has stated the words I, too, live by: "I don't need to pay someone to screw stuff up. I can do that myself for free!"
The woodgrain on the dash of a '70 model was based on the model, not the interior style. A GS350 had no wood grain on the dash, even with a deluxe interior. A GS455 had woodgrain on the dash even with the standard interior (blue code 121, Sandalwood 124, and Black 128). Regardless of the interior style, the only '70 Skylark that got the dash woodgrain was the Skylark Custom. Check out the photos of the '70 Stage 1 used in the Road Test Magazine road test (March 1970 issue). It has the black standard interior and has woodgrain. Here is the interior of a friend's low-option, unrestored '70 GS455. Standard interior, woodgrain dash, just like the car posted earlier. The 1970 Buick GS Sales Ideas training film I uploaded to YouTube a couple of weeks ago mentions the woodgrain on the dash this way: “Inside the GS series instrument panel features an insert of black camera grain vinyl while the GS455 series instrument panel features woodgrian appliqué.” I do not know how the woodgrain was applied to the '71 models.