Dambusters Bombsight.
Bomb Sight. UPDATED VERSION. Now with mock locking pins to enable alternative Dam settings
Further research, prompted by a helpful purchaser, has enabled me to get even closer to an accurate reproduction of this bombsight. 
Based on the bomb sight that 617 Squadron may have used on the Dambusters Raid.
I have studied photos and descriptions of the bomb sight that may have been used on the dams raid. It is said that not all aimers used it but Plt Of John Fort on AJ-J piloted by Flt Lt David Maltby certainly did and it features in the Dambusters film.
It measures approx 18 inches long when arms are opened. Made from solid hardwood, with brass fittings.
It would be a useful educational aid to teaching the remarkable achievements of 617 Squadron as well as  Geometry/Trigonometry , for example to demonstrate how the dropping distance for the Upkeep Bomb was arrived at. Templates to set to Mohne or Eder Dam are supplied as is information for alternative dropping distance and map of Mohne Dam with drop distance etc marked on. 
Please note that I am not claiming this to be a replica, only my honest interpretation of it. However, do look at my feedback to see what others think of it and my other related items.

_________Now supplied with display base, see photos_________