That plastic lock is the worst. It's a known flaw on those older machines. Just replace the part, it's cheap and easy. Your mixer is probably fine otherwise. I've done it twice on mine. It feels like a total design fail but the fix works.

Brass followers were a solid call for that old cam.

Yeah, the "random guesswork" part feels spot on. I had a paper flagged once and it was a total mess. I just ran it through a few different checkers and they all gave me wildly different results. Ended up having to just trust my own work and the feedback from my professor. Those tools seem to create more stress than they solve.

My old foreman in Texas swore by that towel trick, miam11. He'd keep a scrap of terry cloth tucked in his belt and give every brick a quick pat. It sounds small but it saved so much time on cleanup later. I tried the dry sponge last week on a misty morning and it worked just as well, kept the joints looking sharp. Those little tricks from other masons are worth more than any fancy tool.

That "swap materials without telling me" part is brutal. My cousin's contractor pulled something similar with flooring allowances on a kitchen reno.