One of the blessings of desktop publishing is how easy it is to create convincing paper props. That applies not only to the technical process, but the imagery of documents. At this point in time there are...what...two generations that have never used a typewriter as anything other than an affectation? That makes any typewritten document "vintage" and considerably simplifies the suspension of disbelief needed to make a prop convincing.
For those particular projects you should check out Kingthings Trypwriter, a mildly distressed typewriter font that features a full character set and a free license.