Hi mate,
I can't help with the front mech itself, but I am selling front derrailleur shims which fit a 28.6 and a 31.8, if you find what you are looking for in the wrong size or you want to open yourself up to more choice.
Shimano Front Derailleur Clamp 31.8 £1.50
Shimano Front Derailleur Clamp 28.6 £1.50
Let me know if interested.
Cheers