This assembly is from a Dailey window from 2008. It made by Truth and
has a double swing arm.
The long arm from the window attachment point to the handle is 5". The 2 remaining arms are 4". I hopes this helps. Based on the dimensions I saw on the 39-316, The 5" arm on mine is 4", the 3 1/8 is good And the 3" between the screw is good too.
The hardware is very similar to that seen in the video "How to replace a casement window operator".
Can you help me?
Jack