Thanks very much for all the info and the link to your shelf liner mock-up post. I’ll dice into it more when I can get a moment.
Since I’m working directly on the clay last, I use a different approach, with using a pair of big screws to hold each pair together, and leather handles on each part to have something to grab onto. I’ve developed a 3-part last that I’m looking to see how it will come out when I’m at that stage (fingers crossed).