The Seneca needs an extension bed to give it full usability. This one was missing its original bed. I figured that gear racks are readily available through suppliers like McMaster-Carr and Boston Gear. Should be a simple thing to source a suitable rack, fabricate the wooden bed, and make a rail.
Turns out, not so much. A machinist friend schooled me on how these things work. Essentially, the existing rack and pinion is based on an obsolete size (a demetrial pitch of 46). Today’s closest match is a DP of 48, but that’s not good enough. Using the old pinions on the new rack would cause binding in use. That leaves few options: Have a shop fabricate a new rack with the obsolete specs; replace all the existing rack and pinion parts; find a donor camera in irreparable condition and scavenge the parts from it. The first two options are cost-prohibitive and logistically difficult; finding a donor to cannibalize seems the only workable solution now.
So, I’m trolling for a parts camera. I can’t foresee continuing the restoration of this camera without the proper extension. Drat.