I've searched the world over for those dang bolts and haven't found them yet. I bought a pair of the Tektros(actually Rivendell's version called Silver) and the rear brake bolt just isn't long enough and I didn't want to drill the fork for the recessed nut.

Another option is to simply buy two front Tektro R556s.

Here's what NOT to do for your rear brake:

bike is presently sitting at the LBS to get this brake bolt fixed; one of the mechanics is a long time pack rat and probably has some bolts that may work. We'll see when he gets back from vacation.

Note the 27" rims; the long reach brakes were still necessary on this old Raleigh Sprite.