We started with the smallest part, the head. The screws are freed and the top plate can be taken off.
The spring controls the movement of the top prism which still stucks.
The steel pin on top has been removed and freed some extra markings. The serial number is stamped twice and the maker of the head is Askania Werke (bxx). All other parts of the periscope are made by Leitz (beh). This is not uncommon.
The prism sits in a frame that must be able to rotate. The WD-40 shown in the photo provided the solution. The thick glass plate has a small chip, but after remounting it, this will be invisible.
Next problem is at the lower side of the head section. This side is protected by a simple glass plate, but you need a special tool to loosen the ring. The inside was dirty, so it had to be removed and cleaned.
There is always friendly specialist that can make the proper tool.
Here the glass plate and the ring. It was cleaned of course.
We found some chips of glass. It comes from the side and will have no influence, once mounted.
Each section has several cartridges to keep the inside dry. The middle circle is for the bar that leads from the observer part below up to the head to control the elevation of the prism.
Solving some 1 mm problems.
The outer casing was removed to give the sliding bar some grease.
One of the drying catridges is broken and stucks. We have taken out the crystals because we don’t want them hanging around inside the head.
The head section has been assembled, the glass has a new grey sealing to make it waterproof again.