Block chain = a 1" pitch chain (skip chain) with solid metal links between the teeth (short links)
Egg carton rack = a rack that looks as if it could hold large eggs (round or ovalish openings)
Biscuit light = a rather ugly fender lamp(usually) that is sort of wedge shaped, with upper and lower halfs
Butted spokes (not that kind of butt) = a spoke with thicker shank/ends at threaded area and or spoke hole areas
T-Cup lamp = any cupped shape lamp, my be very shallow like a saucer, or deep like a coffee cup
Truss fork = front fork with added rods between axle and top fork stand off. thes run the gambit from a Strong Schwinn double-Duty fork to the Schwinn hollow decorative (mostly) truss rods. (not just Schwinn cycles)