Thanks again for all the input and for pointing to some very helpful resources. My morning progress is pictured below. All cogs successfully removed from the 5-speed Perfect and the 6-speed (wide) NW. After some time with the compatibility charts and a caliper, I think with cogs on hand my best mix-and-match bet might be 14, 16, 18, 22, 26, with the smaller 3 from the Perfect and the largest 2 from the NW, using the Perfect body. I'll try fitting together this afternoon. 14, 16, 19, 22, 26 was my first thought, but the 19 from the NW is threaded and doesn't fit on the Perfect body (which requires the 3 largest to be splined). If this doesn't work out, I believe I'll be in search for an E15 for the NW.
Top: 5-speed Perfect (14-23) Bottom: 6-speed (non-Ultra) New Winner (13-26)