Jim - The Master Airscrew 9x4 and the O.S. 20 are great combination. You are correct that using modern radio gear saved fair bit of weight and was very beneficial to the flying qualities. I really enjoy the New Era III and had quite a few flights with it (also it is fighting the "flying roster" with quite a few other aeroplanes).
Since building the New Era III I was very fortunate to be given an Akromaster kit (partly built) to complete the construction and to add to my collection of "vintage" aeroplanes (also I did use modern engine and radio gear). The link for my thread on that project:
MK Akromaster Build Handover
Cheers,
Eran