Dave and Rick - thanks for that!
While building this project I've been referring to Ray Rimell's modelling book on the Hannover, and finding some very good tips. I typically wouldn't have bothered dressing up the observer's gun mount, but after reading about what Ray did, and seeing a drawing of how it actually looked, I decided to add some small mods to the kit parts.
The small springs were made from wrapping copper wire (salvaged from an electrical cord) around a #79 drill bit. The wingnuts were from some ModelKasten details I had in the spares box. Also added was a wire grab handle that has locating holes, but no handle included in the kit (?). I also cut the locking handle from the side and articulated it back a few degrees. They seem to be mounted on different sides depending on what references you use.
Cheers,
Gary