Hi John,
Nice to see someone having a serious go at a Supercut as they are getting less and less as time goes on. There are probably more Electric units surviving now than Petrol as many bowling greens preferred the electric versions over the petrol powered units due to anti-vibration features of the electric mowers opposed to the thumping effect of the single piston petrol powered machines. I actually have a Villiers Powered 18 inch machine awaiting full restoration that's in rather good condition and a second unit in a much poorer state as a donor machine should the need arise.
As far as sharpening services are concerned there is no one better than Steve Rose at Australian Saws & Blades who is located on Research Road Pooraka. I know it's a fair drive from Willunga but Steve does work from all over Australia so he must know his stuff. I personally use his services and am currently waiting for him to re-open from the Christmas break as I've got a 20 inch reel and bed knife awaiting his magic touch.
If at any time you feel you need to speak directly to someone I'm always available to chat via the phone.
Cheers,
BB.