EK2 C.E. Juncker /full Juncker / with magnetic core with LDO mm L/12 on the ring

EK2 C.E. Juncker /full Juncker / with magnetic core with LDO mm L/12 on the ring
The condition good, but this the piece “ultra rare” because the interesting thing is that unlike usual, the LDO marking is not on the back of the frame but on the ring.
This piece is also a very rare piece, probably by accident or suddenly a piece was needed due to the lack of “private sale” stock, We known as it exists from the manufacturer W&L, it is also marked on the ring and as usual in the upper part of the back, but of its own W&L type piece by piece (unfortunately, I couldn’t find these two missing types, but other collectors can find them and there are also pictures of the found pieces, they were luckier) this is a real “unique” piece.