Yep - there is 5 gears there - and they appear to be assembled correctly, but you can't shift through all 5 gears unless one of the transmission shafts is turning - 1st gear is cut into the input shaft 2nd is splined to the shaft and slides by shift fork - 5th gear is splined to the end of the input shaft and is stationary.
Looking at the input shaft in the pic - the RH gear is 1st, moving left is 4th, then 3rd, 5th and 2nd
First is made when the output shaft 4th gear (splined to the shaft) is slid over to engage and lock the freewheeling 1st gear on the same shaft to the splined gear - power is transmitted from the gear cut into the input shaft to the freewheeling gear of the output shaft transmitting it's power to the splined gear which transmits it's power to the shaft causing the output shaft to turn which is connected to the rear wheels
Second is made when the fourth gear on the output shaft is moved out of engagement with the freewheeling first gear and the splined fifth gear on the output shaft is engages with the freewheeling second gear of the output shaft - power is transmitted from the splined second gear of the input shaft to the to the freewheeling second gear of the output shaft to the splined fifth gear of the output shaft
Third is made when the splined fifth gear is disengaged from freewheeling second and the splined fourth gear of the output shaft is engaged with the freewheeling third gear of the output shaft - power transmission is from the splined input third gear to the freewheeling output third to the splined output fourth gear
Fourth gear is made when the splined fourth gear of the output shaft is disengaged from the freewheeling third gear and the splined third gear of the input shaft is engaged with the freewheeling fourth gear of the input shaft - transmission is then from the input shaft to the third gear - splined input third to the freewheeling input fourth - from the freewheeling fourth to the output shaft splined fourth
Fifth is made when the input shaft splined third gear is disengaged from the freewheeling input fourth gear and engaged with the freewheeling input fifth gear - from the splined third to the freewheeling fifth to the output splined fifth gear
Because of the difference in rotating speeds of the individual gears, it is highly unlikely the engagement dogs and slots of every gear will line up to allow shifting through all 5 gears when the shafts are stationary - due to frictional rotation, you have to hold one shaft while turning the other shaft to shift through all 5 gears. The engine running and sitting still, you should be able to hit all 5 gears both up and down - the engine stopped and the rear wheels turning you can hit all 5 gears - engine stopped and sitting stationary, it's possible not to be able to engage either first or second without 'rocking' the vehicle forward and backward - it's also possible to be able to shift all 5 gears, but it is almost guaranteed that with everything stationary at least 3 three gears can be engaged - either 1st, 2nd and 3rd or 2nd, 3rd and 4th, but it extremely rare to hit all 5 without some movement
If the engagement dogs were missing from the input shaft third gear on the LH side, then shifting to 5th would be an extra neutral
Hope this helps
View attachment 4446
BTW - the detail pics indicate which side of the thrust washers and snap rings go which way - the thrust washers and snap rings have a rounded and sharp edged side and they have a specific orientation