The only reusable part in all those pics would be the 1st gear speed gear. The other three gears are either scrap metal or a candidate for Pro Shift, Face Plate, modification. The sliders are scrap metal.
What do the shift forks look like?
What does the cluster gear bearing shaft look like? Any grooves or pitting?
What do the synchro keys look like? The crown in the midle of the six keys should not have any notching.
What do the hubs look like? Are the grooves without notches or steps?
Your options are many, unfortunately, they are all costly.
