There is an older serie, known to me as the Beckmen imports. Pike and JimSmithSr have some nice ones. I hope they'll start a thread on them as they are gorgeous.
This serie, also with Martinesque headstock, was crafted by Yamaki and was most likely produced until 82. (I found the thread on what everyone thinks of as vintage... It's clear that for some these are older rather than vintage Washburns)
The one I have is called the D-62. It's a classic looking solid spruce/rosewood Dreadnaught with slightly rounded shoulders. Mine is a '78.
If anybody wants to post some pics of other guitars from the same serie here, please do.
I'll start a separate thread on the triangular head serie.