On question 2 I got the answer from Tom Wishon himself which was more the good of him:
"Back in this era when virtually every golf company used the Dynamic taper tip steel shafts in their production clubs, some of the companies would choose to keep the True Temper Dynamic logo and letter style of the shaft name, but they would change the Flex letter designation to be of their own choosing.
For H&B Power Bilt, they chose the letters A, B, C, D for the flexes, A, R, S and X. So the B designates an R flex in the shaft."
Cheers, G