B33 toolbox locking screw

[Mascot910]

I want to remove the toolbox twist turn locking screw to have the box painted. I can open the lid but can't remove the screw. How is the screw retained ? I can see a flat washer but no circlip or retaining but. Can anyone advise ?

[Mascot910]

I have drilled out the old twist  screw and purchased a replacement kit from Draganfly. Excellent next day delivery by post.
Attached photo shows Dzus fastener kit part no 42-9038B cost £7.19 + postage.

The old screw had a shoulder but no obvious cause preventing removal.