My old laptop died mid project last year and I lost three days of work. Now I use version control software like Git for my text files, it tracks every single change automatically. For big design files I do what you said, save a new copy with a timestamp before any major edit. It feels like overkill until your computer crashes and then you're just glad you did it.

Ugh, that hose trick is a total trap. The problem is you can't get any real control over the water ratio, which is everything with mortar. I learned the hard way too on a brick walkway. What saved me was using a cheap 2-gallon pump sprayer from the hardware store. You fill it with water and pump it up, then you can add just a little at a time while you mix. It gives you way more precision than a hose or a bucket, and it's still pretty fast. You get the right thick, peanut butter consistency every time. Never trusting the hose again after that mess.

Read a conservator's blog post that really stuck with me. They argued modern PVA can get brittle and discolor over decades, while a good wheat paste recipe ages with the paper. Your result with the flexible spine after a year proves that point. For my own old family letters, I mix a thin wheat paste because it's reversible with water. What kind of paper was the ledger made from?

Yeah, that 'drape over color' advice is a game changer. I use old curtain liners from the dollar store for the same reason.

Yeah, the "build new muscle memory fast" thing reminds me of my friend who got a fancy new Japanese pull saw. He forced himself to use it on a small bookshelf, and honestly it was a mess. He kept going back to his old saw because the new motion felt so wrong. I kinda agree with nguyen.morgan, it just wasn't the right tool for his hands or how he works. He sold it and went back to his old one, no regrets.