I asked the same thing about 4 months ago. Never got a definitive answer. This is interesting because Chevelle door panels are less than 1/2 the cost of Buick panels. I need to go find me a junked Chevelle door so that I can see what else in interchangeable. I suspect that they may be the exact same door with different door skins. Anybody want to comment?
Chevelle door panels will always be cheaper. There were more Chevelles made than Skylarks. The Chevelle door panels are made of cheaper materials and look cheaper. If you want to stay on the low dough side, buy a Chevelle. Buicks were never known to be the everyday, bread and butter, driver's car. If you want class, stick with Buick interior pieces.
I believe that 70-72 Monte Carlo door panels will also fit. You might even be able to get them cheaper. There are some on eBay. Not sure if the back sections will work. http://cgi.ebay.com/ebaymotors/1970...34206QQitemZ4598908200QQrdZ1QQsspagenameZWDVW Good Luck, Bob