These are two tools I modified a bit to fit the shallow and soft filler and drain plugs better, as the tools with chamfers just do not fit completely.
All plugs, save one, are 24mm size. The rear drain plug is 19mm (I did not have to grind a new 19mm socket, as I have a perfect one left from the bike shop).
I just used an inexpensive socket and box end. Note that the socket is a 6-pointer; important, I think. I could find no cheap 6-point box ends (I've never even seen one of these, though)
Many of these plugs have been mangled over the years by inattentive techs.
I would really urge all to grind away the chamfer - peace of mind, and the tool is not ruined.
And, of course - REMOVE THE FILLER PLUGS FIRST ! ! !
Oh, do not ask, 'What is it?' Let us go and make our visit.
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
Now and then we had a hope that, if we lived and were good, God would permit us to be pirates.