I don't mind trying to vectorize it if needs be, but consider that it'll cost you about $40 or so to get a vinyl CPO printed, and the colours are likely to be off unless you can get them matched (since no way is anyone going to be able to work out exactly what colour red/blue etc should be used from a scan, especially one where the colours are faded anyway).
You would be as well trying to win that CPO on ebay first before you worry about restoring your existing one.
If you scan it, then I would leave the pics at actual size. The resolution needs to be high enough to make out all the detail.