Ok girls and guys,
I´m back but still have to finish some projects before I can take the time for showe more pics
I will post some new pics next friday so stay tuned
Next friday pic. Inside the panel
I don't think there's anything like locks. I think there's just some small flat head screws, probably just wood screws, that were driven through the edge of the panel into the blocks and sloppily painted. Nothing about those screws looks like a lock to me.
Think about it... not all of the panels have it, likely because they only screwed a panel down if it was lifting up.