bornem is a place in belgium, sa tends to be associated with south africa or possibly an american state.
but after a bit of digging it seems they are contractors to car firms. they are/were based in belgium:
February 24th 1962
Most Morris Cars To Be Assembled In Belgium
BRUSSELS, Feb. 23.
All makes of Morris cars, with the exception of Riley and Wolseley, will be assembled in Belgium from the early summer.
Morris cars are now imported fully-built or from assembly plants in Holland. The Belgian firm, Beherman-Demoen, already holding similar contracts for Standard-Triumph and Borgward, will assemble the cars at Wilrijck, near Antwerp, under a contract which provides for delivery to begin on August 1. Meanwhile, in Birmingham, a B.M.C. spokesman confirmed that these Nuffield products were to be assembled by Beherman-Demoen and added that the corporation looked upon the new contract as a further step in its efforts to build up Common Market trade.
taken from
here
this google search returned vague results