Hi Tom,
Build sheet shows it to be originally an NTC-290 Small Cam, CPL-217, built 21/3/1977.
In Australia most of those CPL's were governed at 1900 RPM and were marketed as "fuel saver" "reserve power" engines.
Original Fuel Pump code is listed as 3253.....one of our fuel shop experts here could tell you what governed revs that was originally.
Hope that all helps,
Newto