FInally have a result here on my E4 california 2017 model
this weekend I have fitted the Oxford touring hotgrips OF691
removing the original grips was easy, no need the cut them off
just used long flat end screwdriver up the tube and sprayed wd40 up
let it soak in for a minute and twisted the old grips off with out any damage
new grips install
the length of the grips is spot on, no need to trim
the clutch side diameter was ok just needed to glue it in place with glue provided in kit
throttle side I had to sand down the plastic tube on the bike as the grip was tight, and burr the endof the tube not too much
to take off just enough so I could slide the grip on, very snoog fit (no trimming)
happy with out come in the end
BUT why my Guzzi dealer told me that there was no grips on the market to fit my bike and I would have
to go down heated gloves route is beyond me, I will be returning the groves in due course
Once again thanks for all the help in this thread