Hi,
Yesterday during lunch time I managed to do a quick repair on a friends reproducer.
As found, it had THAT needle screw and believe it or not it had the thread stripped.
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So I had two options, or go one step bigger... or repair it.

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To repair it, its important to fill the
hole cavern with the same kind of metal. In this case a brass thumb screw I had around was used.
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Then it was sawn and filed flush.
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To make the fix stronger, a small drop of flux and tin was needed.
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Once heated, it fills the gap by capillarity. After filing the tin the repair is invisible.
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The owner wanted a long screw and be able to use soft tone needles (thin needles). This reproducer had a triangular needle hole for bamboo needles so I displaced the screw hole a tiiiiiny bit to the left to allow the screw to reach the corner properly.
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Then the needle screw hole was tapped and a subtle touch with diluted paint made the repair to blend with the patina.
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And voila! Ready for another 100 years.
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Regards,
Pedro Martínez.