Well things have changed in the last 15 years. Shimano road RD's used to have an actuation of 1.7mm to 1. Now 10 & 11 speed Shimano RD's are 1.4mm to 1. Campagnolo 10 speed is 1.5mm to 1.
Campagnolo 10 speed pulls 2.8mm of cable and Tiagra 4700 shifter pulls 2.8mm of cable. Seems to me that you just have to swap out the RD for a Tiagra, 105, or Ultegra and run a Shimano 10 speed cassette.. You can keep your Campagnolo 10 speed shifters.
You'll have to do the math to make sure... old Campy 10 speed (2.8 x 1.5 = 4.2), old Campy 10 speed shifters/Shimano 10/11 RD (2.8 x 1.4 = 3.92mm).
There you go.
John