Just an update:
I have the Mount, with GOTOSTAR fitted, thanks to My Astroshop and Steve. It works a treat..indoors of course. I will endeavour to do a write up of this system once I get it all together for others to peruse.
Anyway, you cannot replace the CG5 saddle but there are Vixen to Losmandy adaptors from ADM and Kendauzat each around $110 USD.
Couple this with a Losmandy D series dovetail...$199 Aust this setup is looking pricey.
Alternately I have asked a ATS if they can get the Losmandy radius blocks for the D series dovetails (they are available in the US) and am thinking of attaching a 10mm alloy plate on top of my vixen dovetail (via screws and tap) and attach the radius blocks a la Losmandy style. Bingo! Poor man's Losmandy. There is nothing wrong with the vixen dovetail...it's just the method they employ to attach it to the OTA re: screw spacings that is wrong/bad/poor.
I also asked about the Losmandy V series dovetail as it also utilises a radius block (albeit somewhat smaller).
If it all goes south I'll maybe try making my own radius blocks..breakout the file! I can feel a blister coming on.
Anyway I'll await the replies and take it from there. Radius blocks are available from the US for around $55 USD. Using my own vixen dovetail, attaching a 10mm plate to this and Losmandy radius blocks appears at this stage to be the cheapest option...for a good solid OTA mounting.
As I resolve this I'll keep this thread updated...someone might find some of the info useful.
Thanks to all those so far, especially John G.
P.S:
I thought I'd post this Australian link:
http://www.starstuff.com.au/index.html
This guy appears to be making dovetails and other stuff right here in Melbourne. I've contacted him by e-mail. Others may find this link informative.