Lawn Mower Striper Stowaway V2

Version 2 of my original Stowaway hooks.  

Unfortunately, after the maiden voyage, I adjusted the push handle on my mower with the striper stowed and the print-in-place hinge gave out.  Redesigned the clamp, featuring a tight tolerance recess for a washer with the thumb nuts at the bottom.

Future versions will likely include a linkage to engage/disengage both hooks simultaneously.  I welcome remixes and design assistance from anyone who would like to improve this further.