Medieval scams
Trying to think of various fake items that medieval grifters and con-artists would have sold, like pieces of unicorn horn (to cure poison and sickness) or wood from the True Cross. I've been searching on google using 'medieval scam', 'medieval con artist', 'medieval snake oil', 'medieval fake unicorn', 'medieval unicorn horn true cross' and the like. So basically I'm looking for the kinds of counterfeited things that some guy in a back alley would sell you out of the pockets in his trench-coat in the middle ages.