After working with this second batch, I want to make something clear. If you want to just clean these up and paint or use as is, fine. If you want to disassemble them completely and restore every part to nice condition and proper function,I'd say forget it. The rust on these is much worse than the first one I got. I got the plates to move and finally freed up the trap door latches and hinges somewhat.
I managed to get both screws out of 1 of the stocks. The lower screws on the other 3 would not break free. Kroil soak, impact driver, nothing breaks them loose. I drilled the heads off to salvage the buttplate parts, but am left with a stock bodies with a headless screws and sling swivels in them. So I'd have been fine just to clean them externally and paint, but that was never my intention. I guess I could tape some gas pipe in them for kids to run around and have battles with.
Side note- I noticed one of the stocks rattling when I unboxed them. There was a complete cleaning kit in one of the stocks, but it was more rust than tools I think.