Have just come back onto the forum after a break and read your post. Have been flat out on restoring the German 10.5 cm howitzer here and a www 2 Ferret Scout Car.
I have been collecting lots of info on 10.5 cm howitzers from our good friend Herbet Jager in Germany, and from his book and from Maj Bill Billet's book on WW1 war tophies. Have received 5 info packed letters with some digrams and sketches and tech specs particularly as he went to some trouble to correctly identify our weapon. Even he has had trouble with working out who actually built it as it obviously outsourced from either Rheinmetal or Krupp to a firm he had not heard of with initials RWF stamped on the breech block. He has made a guess at the meaning of this.
I have also just put togeher a power point presentation with about 150 slides of our restoration of the gun from its arrival, complete stripping, except recuperator, new trails us riveting them with lots of manufactured parts and the gun almost back ready for a paint job. Waiting on new wheels to be made the traditional way. Anyhow what sort of info are you after?
Tim, would you like me to write to Col Jager in Germany (he is not on email) and see if would be okay to pass his address on to you to contact direct. This snail mail might take a couple of weeks but I have found him a mine of info.