This summer I bought a Brooks B17 Honey. Hotter than your grandma's '85 Crown Vic. Got it from Nashbar during one of their frequent sales for less than $50. It sat in my closet until a couple of weeks ago.
Sadly, I didn't take before pics, but here is what it looked like:
The objective: make it look like the svelte Brooks Swallow, "Antique Brown", cost ~$300 (?)
I read the FGG page on modifying Brooks saddles (linky: http://www.fixedgeargallery.com/articles/brooks.htm)and searched the forum archives. That guy used an angle grinder, but I used a Dremel as my weapon of choice. I used some tape to mask off what I wanted to cut, and then started rocking out. Unfortunately my dremel has taken some abuse over the years, and now only has two speeds - off, and Kamikaze!! It burned through cutting wheels like nobody's business. I ended up using three or four cutting wheels doing the first side. The wheels didn't wear down, they just got really smooth and stopped cutting. My apartment smelled like burning dead cow for quite a while. I imagine there is some sort of tool that is made for cutting leather that would be well suited for this purpose. I imagine such a tool would be called a "leather cutter".
After I cut the first side, I used the piece I cut off as a template for the second side. Rinse, lather, repeat. I didn't cut quite enough off - there is still a little bit of the stamped label visible. I need to trim it a bit more, but that isn't too easy with just sandpaper and wood files. I will try the dremel sanding drum next. Still, it looks presentable.
My saddle wasn't completely broken in when I chopped it. I had it on my bike for about a week, so it probably had 100 miles or so on it. It has about another 100 miles on it now, and so far, so good. I only weigh 150 lbs. so hopefully it will last for quite a while. The saddle is definitely less stiff that it was before, but I doubt it will be a problem. We'll see in a couple of years. If it doesn't last, well, that is the cost of good science.
Another note: the saddle is darkening nicely. It is nowhere near as dark as "Antique Brown", but it'll probably get there some day. The original color was just like the top pic. Ingredients: Proofide and ass sweat.
This pic makes the side look uneven, but I think it is just from shadows. I'm going to sand it some more later. The bike is an '05 Bianchi Pista, a replacement for my poor conversion Raleigh with a bent frame that was cannibalized for another bike. If it was a dog I would have shot it.
That's right, it's a kangaroo bike. You know you want to be just like me when I grow up.
Stick a fork in me, I'm done.