Thanks to Peter Y for the tip on Wild Guzzi
Twisted Throttle (US importer of SWM equipment) sells an upgraded lock type for the Guzzi side cases. Part number ALK.00.165.16302 for the 6 lock set (including topcase).
The photos on the web page show the older type, but the upgraded units are what I received. $26 +shipping includes 2 keys, new retention clips, and 6 locks:
Easy to install by prying the old clips off, inserting new lock, and re-inserting the clips.
Old keys/locks on the left, new double bit keys and locks on the right. Major improvement.
Owners of the older style latches shown below have mentioned that transferring the older dog-legged 'latch' from the original locks to the new was required for proper operation, but do function once performed: