Hi Lionel,
Here is the page from the Spare Part Catalogue for the 1941 Chev and Maple Leaf trucks. Don't forget that it shows the USA/Canadian left hand drive truck. Our right hand drive vehicles have the battery on the other side and an accelerator linkage going across the rear of the engine.
If you look on the left side of the page you will see Part No. 2.028 (SHAFT) which is driven by the pedal inside the cab, is connected with 2.033 (LINK) to 2.108 (LEVER) which presses onto 2.100 (SWITCH) on top of the starter motor.
Hope that this helps.
By the way, be careful starting an engine that has been standing for years. Many people look at the oil on the dipstick and because it is clean looking think that the engine is in good clean condition, all that means is that the sediment and carbon which turns oil black, has settled by gravity to the bottom of the sump and could be picked up and spread through the engine causing major damage.
Regards Rick.