I honestly don't know what clutch lever is on my T150. I do know that it's a RH lever from the position of the cable hole and slot. The distance between the holes is 1". '72 parts book gives D3657, '74 gives 60-3981 for the same lever. What's the difference? I would prefer lift over ease of pull.
The '71/'72 levers that I have are 0.99" pivot to cable barrel. Left/right are the same except for the side of the cable slot. Look at the parts book illustrations. The 3657 is the alloy lever, the 3981 is a stamped steel lever.