Is someone able to tell me what to use for a polarizing filter on a Super Speed Graphic with a Rodenstock Optar 135mm lens? Since it is necessary to unscrew the shade to place the filter behind the shade, there is no way to rotate the polaeizing filter. Is there a filter which replaces the shade?

I have a "Spiralite Custom Polarizer Series 6" filter with threads on the front element that accept the Kodak series 6 lens hood. Series 6 threads are 44mm, by the way. I found all the used series 6 stuff in my kit at camera shows.

thanks