This is a 6148 model, serial #4557 made in November 1973, originally with 3 pedals and 2 knee levers, two knee levers have been added. I recently bought it from John Davis for £1800 and have since replaced all the pull rods with stainless steel rods and nylon tuners as some of the original rods were passed it, totally untunable. I tried to get 4 bellcranks for the knee levers but the only place was Mike Yahl in the States and they were $47 each ($188) + shipping which I could not afford so I had to improvise and they work fine. Unfortunately because I have short legs and osteoarthritis in my legs and spine and the fact that I can barely reach the knee levers means regrettably I have to sell it on. It is Day setup so selling as is, I would like to get my money back that I paid for it. It comes in the original case which is in really good condition and would have to be collected from Leicester due to weight. Thanks for looking.