This seems to be a very special Lo1UK35 power supply. The NA-Number refers to the Standard Umformer power supply wich this is not. I believe this is a late war simplified example of the Lo1UK35 Umformer power supply.
Sadly visible is that this power supply was heavily modified post war. I have closed the extra holes but have not found a good paint to cover it up. Both connectors visible were not present when I received it so I added them. They fit perfectly. missing is the type plate, instruction plates and the handle in the middle.
On the inside nothing remains. I had to remove all parts because almost none of it was original. About 75% of holes are not original and post war but I have not filled these in for the moment because they are not visible from the outside and I don´t think I will ever be able to restore this power supply since I have no actual Information for this power supply no pictures no manual NOTHING!!!
These are the only two parts that I believe to be original as well as the fuse holder on the front side.
The case is a loot more simple that the normal Power supply case everything is stamped metal riveted together.
On top the Na-Number is visible again.
Here a part of the NA-Liste where the number is mentioned.
Kriegsmarine Radios and Sonar Equippment 