This is essentially what I do in my spreadsheet (logging the default attributes, along with my updates).
(I don't have any files that could help this process, the older games were all on older computers).
It's definitely a slow-burn and not something I would recommend knocking out in a few days. A passion project you pick at slowly rather than something you try to rush up (because I'm not sure if there's much demand for older games).
You will have a nightmare by the time you get to advanced gens because the data explodes. There's something like 40 Attributes and 80 Tendencies, before even factoring Badges. The league also expanded so between Free Agents, Two-Ways, etc we're talking about 800 players instead of the 400 or so you're doing in the 2K3-10 era.