Search for my post - Combi-cam locks in 2720 with pics and tricks
The Combi-cam can be used as a simple latch. When unlocked, at the combination
setting, it still appears to be locked, even when just latched.
Looks like a square head drive screw put in for semi-permanent, so be careful....
That square fitting just might be the same size as others you will notice in the TM.