only thing I don't like about that one is it mounts on the handlebar not the fork leg
the price is getting a bit more like it though

Don't get me wrong like...but if you're making a part that operates an "essential part of a motorcycle control system" as the police/insurance companies/litigious individuals would doubtless deem a thumb brake, aren't you opening yourself up to all sorts of liability claims if somebody binned it and blamed you?

I have thought about making one myself before now, the small brembo mastercylinder only costs £28 add a good forkleg/steering damper clamp for aound £22. make up an adapter bracket to bring the two together, then its a case os adding a lever and pivot.
All quite possible here in the workshop at work, but as I have no issues with the standard ones on the 998 or 996 which I do use at times to compensate for a lack of engine braking due to both having slipper clutches, I haven't tried to put one together.

It would be even easier if I use the other Brembo rear mastercylinder that I have as it already has a pivot point as part of the casting.

in my opinion for what they are most prices quoted are over the top

That's why companies like Brancatto Engineering pay out a lot in insurance cover each year. As Tony makes so many parts for mainly the older Ducatis he has to make sure he has liability cover as some componets like a front wheel spindle would have major consequences should it fail.

I'd be up to try one out, but not at £400, it would have to be a bit cheaper.

Whats so difficult about rocket science anyhow?

One would ask, why do you want a thumb operated brake?

Thumb brake?
 

Can you use it as a thumb-rest the same way some people use their std rear brake as a foot rest :lol:

Must admit a thumb brake would make my race bike easier to live with! Once I get myself "wedged in" on the saddle I cant move around much and it's awkward for me to get my lickle tootsies back on the footpeg if I move my foot to use the back brake pedal, so I usually ignore it completely on track!
Only ever use the back brake for slow manoeuvres/heavy traffic situations on the road. :rolleye:

One of my colleagues was giving a technical training course to a bunch of people and used the old "it's not rocket science" cliche...

One of the guys in the class replied "Well actually Harry, that's exactly what it is"

Harry had given the course so many times he'd forgotten that he was giving the course to a bunch of NASA engineers :lol::lol::lol: