Find an 82mm filter where the glass is held in place by a notched lock ring. you use this notch to unscrew this ring that holds the glass in place.

You might ask, why not use the outside frame? I tried it before but the frame is too high. The inner ring has a thread that is similar to the outside frame of 82mm.

You slip this down the waist of the WA adapter, tape it place then cement it using a strong epoxy mixture. in my case i used pioneer marine epoxy.

tip: wrap the rest of the WA and ring(especially the thread) with masking tape to prevent your epoxy or cement from damaging the threads and glass.

Attached is a CU shot of a filter sample.