Your plan looks pretty good. Treat the project a little like archeology- associations of materials may be important in figuring out things in the end. There may be clues in what is next to each other, dates on the newspaper packing materials, address labels, etc. Your container inventories should establish this record- I’ve rarely, if ever, felt I recorded too much info. You should probably record where the container was. Photo the space as you go- that may also provide clues. Parts of things may be separated, so be alert to what might go together. Temporary numbers and tags can help with tracking. Getting an overall feeling for the room contents can help, too, before you delve into the details. Have fun!