I don't think the memory expansion is worth salvaging - you should be able to get a working one on ebay for very little money. If you want to give it a try, remove the battery, neutralise the acid with lemon juice and then see if you can repair the damage to surrounding components. Depending on the amount of damage you may also need to fix any traces eaten away by the acid - these are very tricky. Which is why I think it's not worth it.
The floppy, you can try cleaning the heads with isopropyl alcohol.
Congratulations on the find though, she seems in great shape. Extra points for the dot matrix printer! :-)
