i couldn't remember if your other bikes had fastback seatstays. don't some seat lugs have caps for the ends of the stays? they're not as graceful with the caps. a girl i rode with back in the 80's had a Cotten frame, with a wishbone seatstay, campy delta brakes and internal cable routing. they drilled a hole or slot in the seatpost for the brake cable to route through so that the cable was inline with the center cable mounting of the campy delta brake. it was/is the coolest and cleanest setup ever.
second bottle mount-i was just questioning it because your other bikes i've seen only have one.