You might contact Richard Ritter, in a thread over on LFPF he mentions that the 2Ds he an none standard thread and that he had custom taps and dies made for these threads. If you don't know Richard builds and repairs LF and ULF cameras. Here the link to the thread, see post #5. http://www.largeformatphotography.in...l=1#post887150

You could also post a wtb ad here on APUG and also on LFPF for a knob or for a parts camera. Then there always ebay.

Roger

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