Even if you could get a charger (which I think would be unlikely—your best bet in my opinion is to post an ad on Blind Bargains), do you know that the notetaker works? Like you say, it's from decades ago. If a charger is expensive, do the few months of use you'll get from it (because I doubt you'll get more than that) justify the cost of the charger? You certainly won't be able to pay for it to be maintained if it breaks, but it sounds like you don't have the money to pay for maintenance anyway.