After a long wait, and a missing, though refunded shipment from one vendor, I finally received 4 MCX to Co-Ax Converters from ebay.
Not willing to wait after the first AWOL shipment, I ordered 2 flyleads and 2 one piece converters.
The difference in FM radio off the bat was huge. With a slight adjustment of the AF gain and setting Noise reduction to -75db, the signal was crystal clear. SDR# also picked up the 64 Character Radio Data System message, though that come through at a character or two every second.
Next I'll be seeing what luck i have getting anything of substance from Bankstown Airport traffic control.