Which decorative stamp is Medieval (400 - 1400) and which is Victorian (1840 - 1900)?
As historical binders and conservators of very rare and old books it's important to understand every detail of a particular time period's binding style. When we're designing decorative tooling for a cover of, say, a Medieval book, we're careful to use only Medieval decorative tooling. Just because a decorative die is fancy and looks old fashioned doesn't mean it belongs to the correct time period for any given old book. Just like different binding styles mark a time period in history, so does decorative tooling.
We often see binders advertise their tooling style as Medieval or 16th - 17th Century, when all the decorative tooling used on their covers is really 19th - early 20th Century. As historical binders we sift through a lot of misinformation and have to ignore a lot. That doesn't mean the misinformation isn't annoying.
As a word of caution to other book binders out there who copy decorative dies from old books found on the internet: Be aware that the 1800s was a heyday of rebindings. Books published in the 1600s and 1700s were often rebound in the 1800s, and their bindings and decorative tooling reflect 1800s binding styles. A huge part of our current business is taking these previously rebound bindings back to the proper period of the book's publication. So, If a book is published in the 1600s, you'll still need to carefully examine the binding to ensure it wasn't previously rebound in the 1800s before copying the tooling. The same goes for binding styles. (We'll talk about French grooves another day, but please stop putting a French grooves on bindings being advertised as Medieval or early 1700s!)
We know in reality the common person off the street shopping for an "old looking" book or journal isn't going to know the difference, but as craftspeople we should take pride in our craft and do the job right; the details matter.
By the way, the decorative die on the left is from the 1400s, and the decorative die on the right is from the 1800s.