here's a quick list
You can probably interchange just about everything on those machines except for the pumps,washarms, and the timers and controls. The 23 has the whirlpool power clean module pump and the 22 has the Hobart designed pump. Leave it to whirlpool to redesign the bottom of the tank to accept the smaller diameter wp pump. I guess it was cheaper to make a new dye to stamp out a different bottom than use the wp pump with a larger diameter motor mounting plate. Surely it all came down to dollars and cents.
If you want to keep the 22 running forever or close to it, then start looking for 22 series machines and if it's a 23 you want to keep going, the same advice applies.
You could always interchange the timers, program swithces and harnesses, basically swapping out the complete doors and harnesses as long as if you wire up the windings of the motor on the 22 correctly. Comparing the wiring diagrams will help you wire it right.