$340 for a cracked dropout? Just ride it, lol.

So a 70 year old smith told you one thing and now oil is out the window for everything? That is a big jump from one leaf spring. Hot water can work on thin stuff because it cools slower than room temp water in some cases, sure, but that does not mean oil is the problem. Plenty of guys run oil on 5160 and 1095 and get fine grain, the grain size has more to do with your soak time and how hot you got it. I would bet money that razor job in Tulsa had more going on than just the quench. And "grain looked way tighter" from one eyeball test is not really proof of much.

My grandma had a shelf in her garage with about 40 jars, but she only ever used maybe 6 of them for actual canning. The rest held nails, rubber bands, twist ties, you name it. Thing is, she didn't save every jar. She recycled the ones with cracks or weird lids right away. So it wasn't really about keeping all of them, it was about keeping the good ones that still worked. That's the part people miss when they say it's hoarding. Your bike bin sounds the same way, you keep the chainrings that still have life in them, not the bent ones. In my experience the line between useful stash and junk pile is whether you actually dig through it when you need something.