I couldn't wait so I spoke to Michael Miedler who runs the business and he is a gentleman. Very friendly and very helpful. He was also very patient with my German which sometimes struggles a little with some of the German gun specific technical terms, so I just switched to English and he knew what I meant. He said he has had a lot of interest from overseas for whole actions which he is just in the process of finishing a batch of ninety actions. All machining is done in house and at the moment the biggest bolt face is to suit 0.473". He is working on a magnum action as we speak. The action can be had without engraving on the receiver so that one can have their own engraving done.
I also asked whether the firing pin fall is original or shorter and at the moment it is original but he is working on a new model with a shorter fall which means a shallower helix and therefor an easier blot handle lift.
The barrel fitment is as pre-war models and therefore the normal chambering procedure can be used. The barrel thread is M27 x 1.5mm. He is going to email me with a price on a complete action so I will report back when I get an answer.

Waidmannsheil.