I'd like to caution against modifying old parts to fit your old bike frame. If you machine a seatpost, brakes, stems, etc your removing material and possibly putting yourself in an unsafe postion if the part fails in use. The same caution applies to any frame with a dimple at the down tube, a sign of the frame being in an accident.
Just my two cents, have a safe weekend.
Brian
Anacortes, WA USA