½ mark 1916 J - double-punched mintmark?

So, I was entering my German doubles into Numista, and as I was checking the mintmarks of my ½ mark coins, I noticed this:



(Yay for my new USB microscope, I couldn't get a decent picture through my phone and magnifier like I usually do!)

I haven't been able to find any info online, and the local library didn't have any German coin catalogs, so since I had so much success with the Swedish 2 kronor 1950 double-punch - does anyone else here have any documentation of this one?

made on the morning of a first of januari?

It appears to be a large J over a small J. Congrats!

Citeer: "Mkichline"​It appears to be a large J over a small J. Congrats!

​Sounds cool - is it in any catalogues you know of? :)