The bronze English Tippler in the UK was always bred only for exhibition.
The German 'breed' was made from a 'mix' of bronze English Tipplers and English FLYING Tipplers imported into Germany prior to 1936.
The Germans had a Club for the 'breed' as long ago as 1936 when of course there were good contacts, ended by the WW2 and then the Berlin Wall, so the German 'English' Show Tippler was 'made in the DDR, with which even West Germany had little or no contact!
So, what went on . . .
In the UK the English Show Tippler was bred traditionally as before, only being exhibited in bronze and with few further 'crosses' being made (one UK breeder did introduce a German bird, before the type etc changed so drastically) and also Dutch Schornsteinfegeer was added at one time. Most of the offspring were 'disposed' of, as unsuitable temperament! (English Show Tipplers are TAME) here, I am going back to what happened in the 1950s/60's and early 70s
In the meantime behind the Berlin Wall in the DDR, things were happening to the 'English' Show Tippler, other breeds were 'crossed' in, notably the bronze Berlin Short Face (which at that time had 'Streifig' colour (a type of red-yellow Schimmel) introduced and also English Long Face Tumbler and then some 25 years ago it seems all the reds produced were culled out of the breed, so losing that red gene that gives such a good bronze colour. Blacks and black tiger were also allowed to be exhibited. Black and black tiger (tiger here in Germany must as a general rule, have all black flights and tail feathers or cannot be exhibited) then blacks from very early on were allowed to be exhibited, as the Germans (most of them) still had no idea that the English 'breed' was only exhibited in bronze. Black tiger became the dominant exhibition colour, with bronze tiger in second place. The self bronze, the 'dominant marking' in the UK is and was relatively rare here in Germany, I doubt any German has ever seen a 'chuck' marking, unless they visited the UK shows and even there the 'chuck' was always rare (it is a 'hand-made' variety like the Bohemian Swallow).
A group of Show Tipplers
