I think Casper's method was pretty typical of the 1960s and earlier when players really had to "pop" the ball to get it rolling over the rougher slower greens of that era.
It's a method I still see amogst the old timers in my club
Bobby Locke is often said to be the best putter ever-- he appeared to hook his putts, and moved his body quite a bit.
George Lowe is another fellow that is legendary with the putter.
Some of the more recent good putters-- Loren Roberts, Ben Crenshaw, Morris Hatalsky, Nancy Lopez, Jack Nicklaus, and Tiger Woods. What do these players have in common other than they putt fewer times than most people?