I understand you are looking for gears for V-8 outboards? They are still available, just expensive! The later versions are 2/5 degree lug engagement like stern drive, but will work. You might look on Ebay to see if something is there at a more reasonable price.
Late model part numbers:
#435120 forward/pinion gear set – 1 set on Ebay
#336569 reverse gear
#337774 shifter readily available
Early model part number:
#394853 forward/pinion gear set
#330853 reverse gear – several on Ebay
#337774 shifter
Dan in TN