Ink from old typewriters was simply carbon powder and solvent bound to a fabric ribbon.
You could theoretically make your own using a charcoal pencil bought at any art store.
You can still buy vintage typewriter ribbons on eBay if you don’t feel like making your own.
There are reams of old paper still languishing in office supply warehouses, everywhere.
You can also buy vintage typewriters on ebay.
They’re actually very popular collectibles.
I used to “age” old furniture to make it look ancient.
An antiques “expert” once offered me a large sum of money for a “primitive” chest I had in the living room, unaware that I’d skillfully made it look 100 years older than it really was.
Faking “ancient” things is not rocket science; in fact, it’s very easily, simply and primitively done.
Want a “Colonial” chest of drawers?
Buy a circa 1920-1940 “Empire Revival” chest, preferably with hand cut dovetails, soak off the walnut/mahogany veneer to expose the pine, oak or maple underneath, let it dry in the sun, smack it with some used, dirty tire chains, lightly sand it in the expected “wear sposts”, smear some walnut hull “ink” on it and then some beeswax then replace the glass/porcelain knobs with round wooden ones.
Voila....you got yourself a nice “Colonial” chest.
You’d be amazed how easy it is to fake old stuff.
http://www.loc.gov/preserv/rt/age/age.html
Yeah, but ink and paper - or vellum or lambskin - is a different matter.
Imagine trying to fake a copy of the Constitution with millions of people eagerly awaiting your forgery for inspection... it would take you 25 years to pull it off.
While you may make something look authentic its provenance needs to be verified as well. That would be done with all the supporting documents and maybe the BC Barry found amongst his mother's belongings.