The positioning of things is a bit confusing from that picture, as it doesn't show the full length of the shaft, but #32 is the bushing for where the shaft passes through the casing on both sides of the tractor, that is why it shows two of them in the drawing and lists the quantity needed as 2 in the parts listing on the right side. #40 is the bushing that goes inside the base of the right brake pedal so that the right brake pedal can rotate freely on the shaft. You tighten the bolt at the base of the right brake pedal so that it is tight on the bushing, and then there is a washer and a circlip/snapring on the right end of the shaft which is what keeps the bushing that the right brake pedal clamps to from sliding off the end of the shaft. There is a similar bushing on the left end of the shaft labelled #54A which goes inside the base of the clutch pedal to allow the clutch pedal to rotate freely on the shaft as well, but the linkage piece on the left end of the shaft for the left brake linkage is clamped tight to the shaft itself so no washer or circlip/snapring is needed on that end of the shaft to keep the clutch pedal and bushing from sliding off the end of the shaft.
The way that the parts are ordered in the picture looks like you are supposed to remove the shaft by sliding it out to the left, and when you put it back in you put one of the #32 bushings on the shaft before you slide the shaft back into the tractor and that becomes the left bushing, and then as the shaft begins to come out the right side of the tractor you slide the second #32 busing onto the shaft from the right side.
I recommend that you get a Service Manual if you do not alreay have one.