[Age of Reason]

And if the original ever turns up, before a chemical examination of the paper and the substance used to create the letters (i.e., ink, carbon, toner), the first thing I'd do is check the back of the letter to see if it was created by impact printing.

All typewritten letters I've ever seen are dented where the typewriter keys hit the page.

I just examined a letter that was typed in 1975, and the back of the paper clearly shows the dents--most especially the dots over letters like "i' and "j", and also the periods and commas--all can be seen to have distressed the page, even now nearly 30 years later.

If the paper of the original is distressed, that does still not guarantee the letter is authentic--a forger could have used an impact printer driven by a computer.

But if the original is not distressed, that by itself would likely mean the letter was not typewritten.

[dougd]

Another thing to look for would be the cross-hatch pattern of the ribbon. I recall that was fairly visible with a magnifying glass, except maybe for a brand new ribbon still loaded with ink. Do your old documents confirm this?