A little information, and a little more mystery to figure out. A generic search for crystal plates eventually yielded more examples of this plate:
however, they are listed as Tiffany and Co.'s "rock cut" pattern. The series is still made but in a limited number of pieces (no more plates), and I cannot find reliable information about the true introduction of the pattern to the Tiffany line.
Many resellers note a "made in Germany" sticker on their items, which is certainly consistent with a P&P connection.
I have seen the pattern attributed to Van Day Truex, who was Tiffany's director of design during it's 60's heyday; he was largely responsible for shaping the update of Tiffany's aesthetic in china, crystal and flatware. His mid century tenure was between 1955 and 1967; another person took over the position for about a dozen years, and he was at the end of that time (1978) coaxed out of retirement to take over the position again - though he sought a replacement nearly right away- he died in April 1979.
I have seen two casual sources claim this pattern was introduced in 1994 - one a ebay-type reseller and one poster in this forum in a 2008 post. I actually don't know myself but tend to doubt this if Truex designed or commission the design of this pattern. Perhaps certain pieces were introduced or the pattern re-introduced at that time? I would welcome any information settling the question.
Another interesting point. My Peill and Putzler marked plates have NO Tiffany mark. Most resellers are quick to point out the rather conspicuous etched "Tiffany and Co." mark on their "rock cut" wares. There is no such mark on my plates, only the molded P&P mark in the image upthread. Some do note a sticker with "made in Germany" but NONE ever note the molded P&P mark. I have scoured what pictured of the underside of plates and cups their are, and have not detected the molded mark - though it might be there and the images simply not revealing.
So when WERE my plates made. Did P&P sell them under its own label? Were they a P&P design selected by Van Day Truex, or did he create the design himself for Tiffany? I certainly would like to know. Any sliver of information on any point would be welcome.