To be sure, neither of these is a featherweight.

My 105mm NSW (the newer multicoated incarnation, Copal shutter, 77mm filters) weighs 605 grams with retaining ring and caps, 576 grams without according to my not-NIST-traceable kitchen scale. The 1988 Fujinon catalog says 570 grams.

The 1979 catalog says the 105mm SW (single coated, Seiko shutter, 67mm filters) weighs 405 grams, about 30% less than the newer version. Really??

As a side note, that same catalog says the 90mm weighs 20 grams more than the 105mm. Hmmm...