Hi Myles, I realised I lied, I don't have a REAR arb, but I do have a front one. I'm going to try adjusting the rake anyway as a first step...
You're right, I don't need the gear indicator in the middle of the box, but at the ends it is handy. There's only about 800rpm between 5th and 6th and at those speeds I'm in the 'small' bit of the tacho, so it's difficult to tell anyway, so the indicator stops me trying for 7th. At the other extreme, I can do 80 in first, so by the time I come to a corner, I can have a lot of gears to shift down through. It's really good to know exactly how many to knock it down by to get to the gear I want (normally 2nd or 1st) without trying for -1!
C