I got lucky and found the guy that rebuilt my engine 47 years ago and they couldn't find valves back then.They used two cylinder John Deere valves,but he couldn't remember which ones.After hours and hours of searching I was able to figure out which ones,the intake valves from a John Deere B,serial number 9000 and up or an intake valve from a model 50 John Deere.John Deere part number B2863R.
Do you have to re machine anything on them? Length Diameter or Keeper grooves?
Same valves as in a L/Pl Twenety, Twenty Five and Twenty Eight, if that helps.