Taken from my old white rev1 where it served for many years.
330mm overall diameter. Nice round large radius grip, a little worn but only a very little. Very good overall condition and complete as per the pics including boss and horn push.
And here it is in situ.
Nice factory look in my opinion.
£75 collected or can post if p&p is paid. Collection preferred.
In Cambridgeshire, PE29. 1 mile off A14 and 5 miles from A1.