Re: Outboard Conversion
Try places like
www.tcoutboard.com. There were lots of tiller 28s, and they may have one to strip for you. There are other outboard salvage places, but that's the one I know best.
You won't want to buy new parts, I'm betting.
You can also watch ebay. Tiller handles turn up from time to time. I'm not sure exactly which outboards are compatible with yours as far as tiller handles go, but someone will probably know and chime it. It's a pretty big range, I believe.