How to add parts common to several devices?
I'm planning to write disassembly guides for several related electromechanical calculators. Since these things haven't been produced for at least 50 years, I felt it would be helpful to supply detailed specs for each part so that if a part were broken, it could at least be fabricated if a dead for-parts calculator couldn't be located.
Many of the parts are common to all the models, but some are unique to one particular model.
To be clear, the parts aren't standard things like screws, but rather shafts, cams, gears, levers, and so on that aren't commercially produced anymore, but could be fabricated by someone with access to a maker space.
So, what's the best way to handle something like this in iFixit?
Is this a good question?