Here's a good example of a PD150 that would have been printed very late in the print group 1 150/350 printing.
It's a PD150 that a member posted in the two name thread a Konetchy with Jennings portrait on the top.
Konetchy Jennings.jpg
Konetchy was printed with a Hindu but Jennings was the last addition to the print group 1 subjects and the only 150 back he was printed with in the 150 series was Piedmont. So the Piedmont sheet this card came from would have been from close to or in the last stage printing of print group 1.