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You are right on target there with a Belgian origin.
The firm produced bottom bracket assemblies, cranksets and headsets.
Their headsets were stocked by Ron Kitching in Britain BITD. Listed in the RonKit handbook.
The forum had the subject of Belgian produced chainsets come up within the past year in this forum thread -
https://thecabe.com/forum/threads/as-thor-5-speed-my-latest-mystery.124781/
On the bicycle discussed in this thread its chainset was marked with an HF digraph which turned out to stand for a Walloon firm called Hermesse Freres, based around Liege.
Products by your maker were often/usually marked with a WF digraph. The marking on your bottom bracket cup is the more common one rather than the winged W on the crankarms.
Turns out the W stands for the family name of Woit - two brothers.
I asked the question regarding WF products of a Belgian cycles/cycling expert on another forum and received this helpful detailed response -
536
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EDIT:
correction - referred to the symbol on your bottom bracket cup as a digraph. it is actually a trigraph since it shows the initials of the two brothers, T. & F.
the die used to strike the symbol was not always in good alignment with the work surface and in some cases the T cannot be seen while in others the F is faint or missing.
my error: my first sighting of the symbol was in the Kitching Handbook and the T was not clear. incorrectly interpreted it as a seraph on the W so always thought of the brand/name as WF rather than the correct TWF.
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