>>10357369>>10357499>>10357579That's mostly what I collect. There are some collection guides I know of but they are magazines, particularly for keshi (Comp Rex, PVCMagazine, various "encyclopedias" for series such as Ultraman, SD Gundam, etc.). They have photos of all the figures, the booklets, and often the gashapon display art.
Some of these are older issues and are quite expensive/rare, but for some you can occasionally find scans online.
Not an ideal format but better than nothing.