次回この記事の日本語版を投稿します。
In the first six posts, Sprung Leather Bicycle Saddles (Part 1), (Part 2), (Part 3)，(Part 4), (Part 5) and (Part 6) we took a look at various leather saddle styles from the 1950's: (800 series), (750 series), (900 series)，(500 series), (600 series) and (1300 series) respectively. And, in the previous four posts (Part 7) , (Part 8) , (Part 9) and (Part 10) we looked at tools used to maintain sprung leather saddles, specifically the "hammock saddle stretcher", "saddle spring spreader" , "saddle box end wrench" and the "saddle nut transfer spanner".
In this installment we shall take a look at a dual purpose tool.
As shown in the illustrations below, the top half is a brake lever nut spanner, and, the bottom half is an "alligator saddle nut spanner".
Here is the dual purpose tool.
Made by Hataya Tool Co.
Again, the top half used for brake lever nuts as we shall see in detail in a future post. 
And, the bottom half, is an "alligator saddle nut spanner".
Let's take a closer look.
The alligator mouth-like opening is designed to accommodate assorted nut sizes.
The tool has a flat thin profile enabling it to easily fit in between the narrow spring coils.
Compared to the "saddle box end wrench" this "alligator saddle nut spanner" is a one-size fits all tool, no need to worry about what size the nuts are.
Simply slide it in between the coils until the teeth make contact with the nut.
The teeth instantly bite the corners of the applicable nut; thereby preventing any chance of slipping.
With its thin flat profile, and, unique alligator mouth-like opening which eliminates the need to match spanner size with the size of the nut, the "alligator saddle nut spanner" greatly facilitates loosening and tightening saddle nuts. 
Definitely a handy little tool to have when disassembling and reassembling saddles.