Looking on ebay for a socket and I see a bunch of 36mm oil filter sockets. Anybody tried one of them? They are 36mm, 6 point. If they're made/measured true why wouldn't they work? The prices are right and local availability is slim to none.
BTW, most sockets have a taper on the beginning of the sockets throat. That's OK if you're dealing with a full depth nut, but the steering head nut on the FJR is thin for its 36mm size. To make sure you get full contact and decrease the possibility of nut damage, grind the leading edge of the socket down till the taper is removed. That way you'll get full contact on the socket. This is commonly done on sockets used to disassemble the primary drive on HD's.