What you want does not exist as there is a broad brush of repair with no broad brush repair sub that I am aware of. Plus the topic is huge. There's wallpaper repair...that's a thing. Leather care and repair...that covers shoes, purses, watch bands and is a hugely broad topic. Plastic repair is about as huge. I can stitch a steering wheel cover or use hog nose pliers in my car or I can use the same tools/techniques with furniture. See how sideways things get? I'd recommend focusing on a tradecraft then ask the questions nicely, as you have done, in various related subs to find people/posts that may help.