</font><font color="blue" class="small">( Believe it or not, the keys that came with my tractor are Toyota car keys that someone has filed down to work. So like you said, a key is just for convenience but it's absence does little towards security. )</font>
My yanmar 1700 came with a generic 'echlin' key/switch from napa.. I wanted a spare key.. but you can't buy a 'spare' without buying a switch.. as they are just generic stamped out units. I found an old cabinet key with nearly the same size groove on the correct side. I cut it with a small file set... in about 10 minutes...worked great.. /forums/images/graemlins/frown.gif
Lawnmower keys are like this too. At work, we take a few pices of sheet metal.. lay them together and cut dupe keys out on the metal bandsaw for the lawnmower.. works for cat battery keys too... Takes about 5 minutes to cut 6 keys at once.. As a side benifit on the cat key, is you can grind the ear off on the prongs.. and then retract the key after turning the battery switch on...
Soundguy