Ping founder Karsten Solheim sounded a revolution in golf club design with the introduction of his first putter in 1959. "I've got a name for my putter," Karsten exclaimed to his wife, "Listen to it PING." Karsten began manufacturing the putter out of his garage in Redwood City, and the rest is history.
The original PAL (I believe late 1970's mfg) was of the Anser style but with a narrower "flange" and was heavier. Tom Watson used a PAL in his prime until it was stolen. He had a back-up but about that time he started missing the short ones. The PAL2 was available in stainless and had a longer blade. The PAL line had several design modifications and yours was not the last.