Nice stuff
Yes, this is rather not from Pace.
Not sure about the producer, maybe it was sold via several brands.
Just I have seen once the same design from the Italian company Tec Products, called "Roccia" stem.
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TEC had nice stuff
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I think most cool stuff ever from TEC had been the TEC Poggipolini titan pedals
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Still I somehow tend to believe that the CNC billet-style stem was rather produced in Taiwan already.
Another different design was sold via Acor, Fred Salmon and an number of other no-name brands.
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Can't find a picture any longer, but if my memories are correct, I have seen your stem also once already labled "FUNN". This is a Taiwanese brand around since 1997.