Garrard 301 45 lever sticks

My 301 will not click into 45 and only with difficulty into 78. Have oiled and cleaned all links. Saw that the catch lever (Part 43) when lifted by hand will click in. Have loosened and fiddled with the screw between it and the switch lever (part 49) but no permanent improvment. Am reluctant to bend anything. Any suggestions?
Sounds like it might be the part of the mechanism that keeps it from changing speeds while the motor is switched on (44), maybe the pin doesn't move out of the way? The best thing I can think of is look the underside while you try to operate the speed lever, you should be able to see what's hanging it up. Whatever you do, don't force anything :-o
And wash your hands after you touch those levers ( you've probably heard that before ).