I looked in my one and only Imman Meffert "Hubertus" catalog and don't have anything on the model of your drilling. Perhaps Raimey or Axel can tell you such. I have a Dural frame Meffert Vierling project that I have to get finished. It had an un-repairable broken stock so I am in the process of making another. The old stock has been duplicated and now it's on to the fitting stage.

I have way too many projects.