Ok, not from my own collection but I caught this item on Antiques Roadshow. The railgun was produced by the (pictured) couple's grandfather and his friend whilst they were out in France during WW1. No unit was mentioned, but I think it still constitutes "trench art". Amazing detail, and the parts move so accurately. Fantastic item.
A few more pics - apologies for the small pictures but I accidently changed the size of the screen grab and the programme was live.
