Stock Change on Rem ADL 700

Can any of you give me the year that Remington changed the shape of the wood stock on ADL 700 Remingtons.
My brother has one built in the early 80's and i saw one at the range Sat. that was different in shape near the end of the stock.
The owner said it was factory original and that he bought the rifle somewhere near the mid 90's.
Also when did they drop the wood stock in favor of the less appealing plastic stock??
I like the old style better.

mike