I’m in the process of building the Eric Tan workbench and have a couple of questions. Normally I’d fine tune each tenon to its respective mortise. Since this is designed for assembly/disassembly, should I attempt to make them interchangeable for like pieces, or keep them specific and label the joints? Also, what finish do people recommend. If it’s an oil, would you finish the mortises and tenons as well? By the way, I have the top done in ash – it’s heavy!