For the hassle of trying to jimmy bits of fragile plastic into a small hole in a tight space, I'd be tempted to replace it entirely for the £10 - £15 cost of a whole new mechanism.
@NotThamesWater started
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For the hassle of trying to jimmy bits of fragile plastic into a small hole in a tight space, I'd be tempted to replace it entirely for the £10 - £15 cost of a whole new mechanism.