I ordered, shaped and drilled two pieces of delrin for my risers but could not find bolt extensions I was happy with [ one of the joys of rual life ].I did , however, find a set of commercial risers that ,with a little work, have worked just fine.
They are SW- Motech mirror wideners from Twistedthrottle.com.
I bought the ones for the FZ-1 [ iirc about $70 ]
Due to the mounting location on the faring,these moved my mirrors forward a little and out about 3/4 of an inch. which works just fine for me - no more elbows.
The extenders are shaped to fit the FZ-1 stems and needed to be shaped to fit my stock mirror stems - no problem I just ground them down to look better. They fit fine ,this was esthetic grinding.
Sorry, I'm a Luddite, so no pics.