One location which seems to have been missed is International Harvesters' factory in Wheatley. I was told by a friend, the later Albert Gibbs, who was born in 1914, and died in his late 90s that he had built Lancaster Bombers there during WW2 while working as a toolmaker on the Lancaster production line.
Hello Redroger
'International' wouldn't surprise me, as they have been involved over the pond (USA and/or Canada) with aircraft.
Herbert Austin (also known to us as Lord Austin) of the Motor Car industry headed the 'Shadow Factories' Scheme and the idea was to use other engineering industries to make aircraft and parts.
Basically, they had to begin to gear up in the late 1930s onward, as the current aircraft factories were not going to meet the huge demand for aircraft and aircraft spare parts and modified parts.
Therefore, some aircraft production and parts would be made in Shadow Factories, by those in allied companies such as vehicle, tractor, combine and other types of allied engineering, who would use their expertise and skill base to build aircraft and aircraft parts, from aircraft Engineers drawings.
This factory seen on the film could really be any engineering company at Doncaster which took on war production work and contracts.
Just to give you some idea about Contracts 1936 to 1946 there are 784 returns (from the Series searched) Contract Ledgers and Files survive in TNA (formerly Public Record Office, PRO)
http://discovery.nationalarchives.gov.uk/results/r?_ep=contracts&_col=0&_cr=AVIA%7CAIR%7CDSIR%7CSUPP&_dss=range&_sd=1936&_ed=1946&_ro=any&_hb=tna&_st=advOne of the set of large surviving Contract Ledgers seen have 100s likely 1,000s of Contracts, with Contract numbers, dates and company names.
For those interested in Yorkshire, part of the London Air Ministry moved to Harrogate in 1940, but they had Offices all over the place in Cities and Towns to handle local factories and its day to day functions.
Mark
