The reverse gear (if it is full length cut) is reversible if the bushing is good.

Now if you are riding local or in a group the extent you go can differ.

What I seen in your pics, kinda, looks as if the input shaft and the high low gear are pitted probably from all the water in the oil, they both have wear and are sharpening which will eventually cause jumping out of gear on deceleration, generally the bolt noise you may be describing is in the planetary/spider gears which also sharpen and often one end breaks yet stays in place so you will want to open the cage (which you did not show). While the cage is open do the bushings and be sure to Loctite the 3 bolts (been there done that, again), if they are sharp replace them. The main gears generally stay decent if the metal has not gotten chewed by them, if so your bill just went way up.

Often times some excessive noise is actually coming from the driven clutch bushing wear throwing the movable face out of round.


Lastly, if the trans is a G it will wine like a cut cat, that's expected but grumbles and the like are not. One way to tell if the shaft and hi/lo gear is bad is if the wine changes tone significantly on deceleration.