Houghy, There aren't any commercially available in Australia that I'm aware of.
www.astronomy-shoppe.com click onto meade link.
I've purchased these and they're great, a quantum leap over the originals. Especially the primary knobs.
$50AUD for the set of sec+prim.
I know that if you source you're own thread and knobs it would be cheaper, but I don't have time for that + all the running around ( cost of petrol, etc)
This was the best way
P.S. It only took 10days from order to delievery