I grew up racing dirt bikes and wearing an original Bellstaff Trialmaster pretty much nonstop from the age of 15 on. Absolutely bombproof jacket that gets better with age - the process of re-waxing it (do it yourself - quite easy) changes the texture of the material and adds a leather-like patina over the years. The jacket also tends to form to the shape of your body...sort of like the way 501s do.
Although I think they only come in black today, you used to be able to buy them in black, red, and -- I think - green. You certainly couldn't buy a women's version. The red ones were awful if you actually rode a bike.. became filthy over time; black was the way to go. They were a staple of the off-road set, particularly the trials (slow, precision riding over obstacles) and the enduro (long distance races through the woods) crowds, but the "Trialmaster" name came from the International Six Day Trials (ISDT) that were the unofficial Olympics of off road motorcycling and were hosted by different countries every few years. I went to the first ever USA-hosted ISDT in Massachusetts in the 70s and everyone was wearing them; most of the competitors had full suits.
My girlfriends hated that jacket because it smelled from the wax and oil, but I adored it. I probably outgrew it in my late 20s/early 30s and stored it someplace. I tend to believe my wife tossed it out in the process of one of our moves. Broke my heart when I realized it.
In a fit of nostalgia, I bought an International Jacket last year (marketing hype is that it was used by British sub officers in WWII, but it is same as Bellstaff except that upper pocket is angled and has a zipper underneath the fold). Looked at trying to buy a used one like my old rig, but the aftermarket prices were a real gouge in the eye.
I was surprised at the sizing -- I'm a standard 42 and went up two full sizes so I could layer something - anything - underneath it. Material seemed a tad thinner than I remember, but still plenty stout. Biggest difference I noticed was that all the brass buttons had a thin plastic coating over them to prevent tarnishing over time; the old ones didn't have that and always got a nice patina. It bugged me in that too-shiny-blazer-button kinda way at first, but I'm over it.
I don't think I'd wear this rig over a suit or a sports coat. First the cut is short below the belt, so you're jacket is always poking out, and then it tends to pull up even more if you cinch or knot the belt. I think of it as true outerwear that goes with jeans, cords, moleskins, whatever.
Great rain jacket and nice break from all the usual faux mountain gear you see around.
Word to the wise: If you get one, do not sit in a heated car seat while wearing it...very messy and tough to clean off.
Hope this helps...