Chasing Korona 12x20 plate holder or light trap repair

My korona 12x20 plate holder's light traps are shot. Research suggests that the only way to fix is with opening up the plate holder which I'm afraid will just destroy it as it is so old and I have little experience with woodwork letalone woodwork this delicate.

Does anyone have sound advice on how to fix it, or advice on where to send it for repair?

Otherwise I cannot use this beautiful camera until this problem is fixed! (Tried the dark cloth trick but that doesn't work either)

Please help!
Cheers


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