Lotsa Dt1 had the right and left change, shaft is double sided and the clucthc cover has the hole and seal, still pick them up.
Why on the right ? try changing gears with your left on an oval track, when the bikes cranked over, if you lucky you might get you foot back , but usually not under.
IF same guy he has 3 of these DT1, back at work next weeks and ill post the pics, he had hard tail, sprung and also stock frame from memory