Clip Boards of the 19th Century called Letter-Clips

A question a while back on a historical writer's loop was searching for when clipboards were in use during the 19th century. Thanks to Carla for her links to the email loop with the answers that gave me further direction in answering this question.
Here are Carla's references:
1880
An Attorney General's report 1880 lists the item.
1887
The Writer Vol. 1-2 referencing a letter-clip with a description of the board.

I found some earlier references:
1842
Below is an image of a letter clip in 1842 from The Practical Mechanice & Engineer's Magazine Vol. 1 Page 32.

The same image is in another magazine a year earlier 1841.

1865
Referenced in the Household documents of an estate.
1871
Referenced in a Patent book as similar to a letter-clip.
1874
A Practical Dictionary with a description of the item.
1883
The New Letter-Clip