Lee,
Where are you based? That might narrow down the choice a little. I had mine completely redone by Paul Stevens at Purely9 near Camberley. Before the fix I had the worst of all worlds, including leaks, wind noise, a blind that would self destruct when used, rattles, squeaks, etc. My previous indy had refused to touch it, saying it was too complex, which was the same story I got when I phoned around. It really is a terrible design...
Purely9 did a great job correcting it, and for a very reasonable price, even though for me it was definitely a glass out job given how much needed doing. The new seals (all round) were expensive but worth doing, and the whole assembly, including the blind, now operates perfectly, with all of the faults cured. I still have one minor problem, which is that one of the adjusting fixings at the front of the main panel won't stay tight and I occasionally have to pinch it up with an Allan key. Next time it's in the shop I might get them to replace the block as it must be worn.
Cheers/John
