Another numbness question....

I got a new bike a couple of months ago and initially used my old saddle with it. I'd always fought the foot and toe numbness issue with. It was a women's selle italia with a cutout. I always assumed the numbness was due to shoes or frame fit. Now i have a bike that fits like a glove and the numbness is still present, so i decided to try a new saddle. At my LBS they did the sit bone size check - sit on some foam and measure. They deal in Specialized, so it's some sort of Specialized fit kit for the butt. Supposedly I fit a 143, but I'm skeptical at just exactly how precise that measurement was. Anyhow, I wanted to try the 130 just to see if it was a possibility, but they didn't have it in stock. I demo'ed the 143 and it was a nice fit as far as no chaffing the girlie parts, but I still get the numbness (although it takes a bit longer for it to set in than it did with my old, wider saddle). I would like to try something narrower. I'm going to try my mtb saddle for a short ride and see what happens. I have pretty narrow hips, so I'm wondering if maybe the 143 is more width than I need. My MTB saddle is 135. I don't think it'll be too comfortable for long rides, but at least I'll know if the extra width is causing the numbness. How many of you girls ride a guy's or narrow women's saddle? Did the bike shop initially try to sell you a wider saddle? Just curious....