Malibu, I have only tried this in a B733, but I have no reason to think it would be diffeent in an NG:
Left CRS set 340, RHS CRS set 010. Engage A/P A and it will fly the CRS of LHS; engage A/P B and it will fly CRS of RHS. I don't get confused with which was master FCC or which was selected first\, or which is master FD or A/P. This is what the a/c does.
Indeed it was demonstrated by a TC on and approach where LNAV was not an option due to a -300 being non GPS for approach navigation accuracy. Fly inbd a VOR on radial ABC; fly otbd on radial DEF: intercept radial XYZ from another VOR; then intercept LOC.
Method: PF flying with own side A/P engaged; PF select VOR 1 on NAV PF and radial ABC; overhead VOR reselect radial DEF. On NAV PNF select VOR 2 & radial XYZ. When radial XYZ is alive select the opposite A/P, i.e. the PNF side; PF selects ILS freq on his Nav and INBD CRS. At LOC alive reselect PF A/P and ILS CRS. This avoids going via HDG SEL as VOR/LOC stays engaged all the time.
I'm noy advocating this as an SOP. It was a demo of how the system could be used and showed the function of the MASTER side.