I recently sold my Brooks B-15 Narrow saddle on ebay, because I prefer the wider seating area of the B-17. With the money I got for the B-15, I ended up buying a Cardiff saddle, for about 75% of the cost of a B-17.
The shape and size are very similar to a B-17, and it felt pretty much like a brand-new Brooks under my butt, on the test-ride.
It looks a bit different than the Adga/Ideale hybrid mutant saddle that was on the bike, before. Give it a few years, and it might begin to look as cool as the old French leather..
I think it looks pretty good on the bike. It might not be a permanent application, but I put it on this particular bike to break it in. See, I have this method for breaking in leather saddles: I ride a bunch of miles on them. The commuter bike gets the most mileage, so the saddle gets broken in faster on it than it would on any other bike.
I'm not sure where the mutant saddle will end up, but it won't go unused. It's too cool to let it lie for too long.