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Hello SteveB,
The Union Bicycle Co. was based in Brooklyn N.Y. and did no manufacturing of its own.
They had several house brands which included Royce Union and Sutton, among others.
As posted above the bicycles were produced all over the world at one time or another.
Your example appears 1950's era Germany. There was a period in the immediate postwar time when exchange rates were such that the Union Bicycle Co. found it economic to have some of their cycles done in the then West Germany.
The same German produced 1950's era Royce Union juvenile machine has had two separate threads here on the forum in the past two years.
Centrix branded hubs were a product of Fichtel & Sachs.
There is also an unrelated Centrix cycle parts marque in France. The french company was a maker of stems & bars in both steel and alloy. They operated from 1927 to 1962.
The cycle's front hub and pedals are likely to be either WECO or Union brand. The pedals should have a marking on their endcaps (if yet legible!

). They are 9/16" X 20F thread. The front hub's barrel may show a marking as well. From what can be seen in the photos provided the bottom bracket assembly appears it may be of Thompson pattern. Here is an image of the bearings arrangement on a Thompson pattern cottered bottom bracket -
View attachment 1349046
The machine's steeerer and headset will be threaded 1" X 24TPI.
Fork blades appear they may be D-section.
Drive chain is likely to be Union brand from the Union Frondenberg company.
Royce Union branded bicycles were sold mostly in chain department stores and discount houses. Not usually offered by bike shops.
Your missing head emblem is something which comes up regularly in online auction listings.
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