In addition to the above posts many mossies(and Airspeed Horsas!) were not manufactured by the design company but by some of our Furniture Manufacturers.I remember seeing photos of Mossie production in the High Wycombe area but cannot remember the company names.

Slightly off topic but every week I drive past Chattis Hill in Wiltshire and wonder about the first flight of newly assembled spitfires out of there.
The clue is in the name,it has quite a slope,presumably take off downhill and land uphill and the only hint from the road that it used to happen are the gaps in the hedges near the road junction at the south westerlyish corner of the field!!now that is dispersed production !!