STop button for outboard

Hi lads
I have Evinrude 8hp outboard. Was wondering where I would get a stop button on it and a wrist key for it. We couldnt get one when we needed it a few years ago and the guy who serviced it replaced it with a makeshift one on the side of the engine. this has now corroded and I was wondering if anyone has any ideas what the best remidy is.
Cheers

if its a little spud thingy that needs held out i used a clothes peg for ages on my yam.