Pat
We've an interesting situation here. We agree that Powers was intended to be a 150/350 series subject.
But, his untimely death limited his printing to only the 150 series T-brands.
I say that Plank was initially printed with Wagner and the 10 other 150-only subjects. And, I qualify why
Plank was printed with a few SC 350/30 backs.
You say Plank is not a 150-only subject.
Regarding our opinions.... Rudyard Kipling said it best.... "
Never the Twain Shall Meet ".
TED Z
T206 Reference
.