Close coupled seal for 2" flush with 100mm OD? plumbing advice

Close coupled seal for 2" flush with 100mm OD? I'm trying to locate a close coupled cistern seal (foam or rubber) for a 2" flush with a 100mm OD and 67mm ID. All I can find is 105mm, 107, or 110mm OD.

The pan recess for the seal will only accept 100mm OD.

Any ideas on where I could go?

Close coupled seal for 2" flush with 100mm OD? to read more on the original thread at Plumbing Advice

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