Lovely bike wrk101 and cdmurphy you've nailed the dilemma. I do have a seat, Selle Italia SLR Max, which my butt loves and it is on all the bikes I ride. I don't want this bike to just hang in the garage, I intend on riding it in the summer switching between bikes. I tried a sprung Brooks saddle on a bike a while back and didn't like the suspension movement of the saddle. I too was surprised at the weight. I have had an Avocet Touring saddle and found that quite comfortable and they do make a racing saddle, Racer I, II and III, but they were made in the late 70s after this bike was made and in America, so couldn't have been the saddle on this bike.
I am leaning towards option #2 and going with my Selle Italia SLR Max saddle. I think it would blend in and look nice, but allow comfort on longer rides. But I'm open to suggestions, because I am intrigued with the look of the Fujita Belt saddle and then there's the process of learning how to restore the saddle. Most are in sad to saddest condition after 40 years of neglect. Finally, like with wrk101's 75 Sekai 4000 Professional they do look so right.