Why not consider Lion Electrics "ProGLow Synthetic Mix?" (Lion are in Perth guys)

As I recall Lion are the 'crew' that started importing that alternative first pressing castor to Castrol M about 6 or 7 years ago. However as you mention, they are in Perth which presents a problem of economic viability to those of us on the East Coast. Castor qualifies as a fuel, and as such ships as dangerous goods with disproportionate shipping costs in preferred 5 or 10 litre quantities. May as well buy Castrol M locally at its usurious pricing. If only running 3-5% castor, its current pricing presents a good case for eliminating castor altogether.

As for buying pre-mixed value added pre-blended McFuel , no thanks. Sadly the couple of conveniently located model shops on this side of the river now only offer overpriced pre-mixed brews, either their own or a zero handling value added pre-package targeted at the newbies and McFliers priced at top dollar.

I switched to it when Castrol M prices shot up

Having recently returned to R/C after a couple of years hiatus, I'm still in 'sticker shock' at Castrol M's current pricing. Mind you, to place it in perspective, Shell's Methanol has risen from AUD$27 to AUD$45 per 20 litre drum in 3 years, and Shell A even worse. It used to be comparable with a refill from your local club's 220, with the couple of dollars difference worthwhile the difference for the convenience. Not so now.

Oh, as for 4 strokes, don't even conside using Castor in a 4 stroke unless you want to spend most of your spare time reassembling valve gear and timing the whole works.

I personally know a fellow who runs his OS 52S exclusively on a 4:1 castor brew, or did so last we spoke when it was half the price of synthetic. He flies 5 days a week and that engine gets an average 2hrs running (training) at low to medium power settings each day. Runs flawlessly. However, his engine does get stripped regularly for a decoking, and inarguably would require less frequent stripping were straight synthetic used. There's a lot of mythology bandied about being my point. There's less devil in the actual detail.

As a former Oil Refinery worker (20 plus years) for one of the majors, I can tell you none of them have a methanol production plant in Oz. They all buy it in from elsewhere and repackage it under their own names.

No disrespect intended woody, but I think you need to bring yourself up to date. Since Oklahoma and 9/11, the rules on methanol have changed. As it is a component in explosives, like nitromethane the purity of product available to the public has since been altered. In conjunction with an increase in price of not only aviation grade methanol in the past couple of years (then check out Shell A and let your jaw hit the floor) , the same marketing and value adding mechanisms appear to have been recently applied to methanol product from alternative distributors to the retail market. eg: BP. Go and search their website and read their technical spec sheet on the only methanol product they offer retail in a 20 litre drum. They won't/don't tell us what the other 10% constituent now is. Can you?

Sourcing fuel components locally in convenient quantities is becoming increasingly difficult and expensive, but its still a lot more economically viable than paying throught the nose for 'pre-blended' if flying any sort of significant hours per annum.