I cannot quite tell from the clutch picture but vixen make a
clutch part. Just note that this has a thumbscrew on it. Otherwise maybe
this or
this?
MyAstroshop or
Telescopes Astronomy may be able to get vixen parts that is the part without the motor assy, but they will take some time. If you buy just the clutch from Vixen...they will not sell to Australia due to dealerships. Sucks doesn't it. Maybe use something like
price USA.
As for the Peg. Check on the bottom of the tripod head and you will find a nut that holds this peg. Just get a suitable bolt to replace the peg. Probably no need to file it to shape, just cut to size fit. You should have enough room to fit a nut on the upper side of tripod head 9and another on the bottom) so the upper nut will not interfere with the mount head..... Maybe?
Hey maybe you guys should get together...you have enough parts to make one good mount.