Additional update... IT WORKS!!!!!
All the missing parts that were missing in order to make this puppy work have been obtained. The Schieſsstockkopf, shooting stock head, was machined by a guy on the east coast that has made a couple in the past - it looks perfect! The Schlagbolzan, firing pin, is an original that came out of a Gr.W.16 collection in California - one of the most complete collections known.
Now that those pieces are here it became obvious that at some point the Gr.W. 16 went under a redesign from the one shown in the manual. The new design was made so that the Zwischenstck, spacer connecting piece, was no longer needed. Not sure if this came about as a way to save material for other uses or as an answer to have extra parts which would lead to extra chances for loss. It could have been a combination of both.
When I first tried the pieces together the pin was sticking in the top cap when I would insert it by hand. It was sticking to the point I wasn't sure if I could remove it at times!!! I checked the measurements and they were a perfect match. so I polished both parts. The pin moved freely by hand, but when attached to the GW and fired the force of the spring rod jammed the pin into the hole - it would not fall back down into the shooting arm. It was suggested that the force of the propellent would push it back down but I knew that it was suppose to drop down under it's own weight.
Taking it apart again I took a closer look at the shooting stock head. On closer inspection there appeared to be the tiniest sliver of 'something' that was coming from the inner shoulder up into the hole the pin went through. The only way I could see it was to shine a bright light through it and use a magnifying glass. Using a small drill bit of the same diameter I stuck it in the hole and twirled it with my fingers for a few seconds. After this it was gone. After reattaching the parts I tested it and it worked perfectly!
The pin punches out, then falls back down, so fast I put paper over it to make sure it was working - the punch hole proves it!
I know a guy who has exact reproductions of the Wurfgranate 1915. I'm trying to see if the guy who made them for me can make one or two for me. They are powered by .303 blanks. Hopefully I can get one of these repros and have a little fun!
