"I took my new Mercian Audax out for it's maiden voyage today and it was a pure joy to ride I'm now looking forward to another 30 years of pleasure on the roads with my steel horse. 
For those who are interested I chose and acquired all of the parts myself over 12 months after researching; gearing, mechs, handlebar types etc...The parts of interest are listed below for anyone thinking of building a Mercian Audax up. 
Mercian Audax Frame with Sportive geometry
René Herse Double Cranks 48/38  & SKF JIS Square Taper 110 mm Bottom Bracket 
Dura Ace 9 Speed Index Shifters
Ultegra: Front Mech, Rear Mech, 9 Speed Cassette 12-27, Brake Callipers, Brake Levers
Vintage 3TTT Gun metal Head Stem 130mm
Nitto 65 Seat Post
Brooks B17 Narrow Saddle
Nitto 105 Alloy Handlebars & Brooks Leather Bar Tape
Jagwire Cable Set
Bespoke Wheel Set: Mavic Open Pro Rims, DT Swiss Spokes, Halo Large Flange Hubs"