Old desk with pencil rail

I think this is an old teacher's desk because of the pencil rail but it came out of a defunct hosiery mill, used in the office. The mill was active in the early 1900's. I have searched to find an image of a similar desk with no luck. Can anyone tell me what this is?

Photos show desk, the pencil holding rail, the dovetail fitting of a drawer and the pull out work space over the drawers.

 

Definitely some sort of office desk. The pull-out was for a portable typewriter if memory serves. That isn't a ton of help, but it may be somewhere to start, or at least put a laptop!