Whoa guys....hang on....put your British engineering thoughts on hold.
Firstly, leaving a parking brake on all the time might not be the best idea for lots of mechanical reasons....just as pulling the cyclic all the way back....and using chains.
I realize there is a huge surplus pile of the things laying around down there after the end of the assisted passage program.
At the HAI I saw the cutest and most effective set of tail rotor pedal locks.....very compact and very nice looking.,....add a long red remove flag with some means to hang it in plain view for all the chopper snatchers to see and you got it whipped.
I am sure someone else saw the thing too....for the life of me I can not recall where I did.....
Keys will remain a problem.