Hi James,
I would have tried ScottLabs first too, so that's a bummer (I hope they have that gauge in stock though). That part you're pointing to looks exactly like a part Specific Mechanical supplies for their manometers (or at least to). I hope that could be a useful lead.
Cheers!
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Chris Bogdanoff
Head Brewer
Heroes Restaurant and Brewery
Rancho Cucamonga CA
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