wolf commented that locksmith's were expensive - maybe shop around a bit?

I watched a local guy here do a lock cylinder - he was embarrassed to
charge $5 for freeing up a rusted cylinder - I would have messed with
it for hours without success ( i did for 1 hour before i got smart)

if you live in a still-civilised area then your two switch solution
is a permanent fix in my book- you can always make it a bit more secure 
with a cheap key lock switch (from your FRAP) for $5.

cant make anything much cheaper than this ....