Yes, women's saddles are wider because women are built differently (thank the lord).
Get yourself a nice Brooks leather saddle - they are lovely, albeit heavy compared to modern seats.
I spent years trying to get on with a 'Flite' saddle and then gave up and bought a Brooks. Fellow cyclists derided my choice of seat on weight grounds, but the ability to cycle for more than 20 miles in comfort was more important to me.
I'd have thought that Brooks saddles were easy to get second hand, they were fitted to a lot of British bikes through the 50s and 60s (afaik).
I might have a spare dynamo here somewhere. However, have you considered a hub dynamo? These days they are much better than they used to be and it's just a case of flicking a switch to get illumination. No fiddling around with adjustment etc. Mind you on a Moulton the resulting spoke length would be very short indeed.
GC