NavList:

Dan, I'm not sure if this question was directed to me but will answer in case it was.  The Polhemus was intended as a celnav tool and the various plotting disks that are included in a complete Polhemus computer set are a better option than the plotting boards. 

The plotting boards were a DR tool not a celnav tool and were used to plot the courses and times to a target or search area and the planned track of the boat so they could get back (esp in the days before secure radio nav was a thing). You can use them for celnav and you set them up just like you would a paper plot but it's not as quick. 

If you choose to get a Polhemus, make sure it has all the longitude disks as these can be scattered and lost over time. Or at least the disks for your typical AO. If you need details, let me know and I can pull mine out and count them (7?). I use the computer side a lot for sight pre-planning but generally prefer paper plots  

The CPU-26 has a tiny plotting area so tough to use if you have eyes of a certain age. E6-Bs are a little bigger but still much smaller than the USN plotting boards. 

The Mk6 plotting board is quite large. The Mk7 is kneeboard sized and very handy.