they crossover...basketweave and checkercabs...I think the checkers started appearing in late 70 early 71 and the basketweaves discontinued shortly therebouts...depending on material available at the Marshall cab factory I guess...
"Marshall History" book by Doyle. It's not 100% accurate, but it has a lot of good info with good illustrations. I would call it the vintage Marshall bible.
You know, I heard there was a book out there something like History of Marshall, or Marshall history. I believe it was written by a guy named Doyle - about 25 bucks I believe.