a short reach brake has a minimum of 39mm I believe (at least on shimano) so if you should have no problem finding brakes to fit. On nutted brakes the post stickout out the other side of the fork or brake bridge and is fastened with a hex nut, there are curved spacer/washers that often work in conjunction with this style of brake. Recessed brakes use an allen nut and the fork and brake bridge usually have a counter sink type of deal which hides the head of the nut, hence recessed. Looks like a seatpost binder bolt kind of... sorry for the lame explanation but I couldn't connect to sheldon brown to get some nice diagrams/pics. PM if you can't find brakes that work... I definatly have extra's kicking about that will work.