I'm just back in Australia after the best part of a year spent in UK and during that time I paid a visit to Martyn Bailey - a very highly experienced maker and repairer who certainly has paid his dues.
I played one of his own instruments and found it very impressive in the English tradition.
Thought his tuners might be of interest - seemed ideal to me FWIW....
http://www.mjbl.co.uk/doubl-bass-machines.html