Although limited in periods covered (stops at 1850), this is a handy, easy to carry reference. Kovel's may be more extensive, but the additional info is often not what you need in the middle of the antique mall checking out a possible purchase. I find I use both, write notes in both, and have many pieces I know are American and I can't find the marks in either. So, what the heck, for ten bucks it's worth having with you BEFORE you buy.

For the time period covered (1650-1850) this is a very useful, almost exhaustive reference. I turn to it when I need to identify a hallmark, and find the illustrations to be very helpful. I thought it was a good buy.

Not until you open the book to the first chapter do you find out that the marks are limited to the period 1650--1850. No marks after 1850.