S Nevada has kind of the same problem and the easiest answer is to take a Schweizer tow hook, input the individual pieces into AutoCad, have parts waterjet cut from wuality steel and then assembled in front of the FAA and recieve an onsite approval instead of a 337. Of course you could just buy the $2000.00 Tost assembly built for 206's and 172's and get it approved onsite.

PS
I am also going to produce a smaller version for folks who hand prop and want a quick release