vintage copy holder w/ratching action

RFQ Details

I'm looking for a vintage 1940 or 50, green steel, probably GSA (Govt. Service Agency) issue, copy holder with a spring clip to hold the paper (letter & legal size. Easel style, adjustable tilt. It has a ratchet along the left side that's adjustable to 1-3 spaces. When the space bar is touched the bar-guide moves down the predetermined number of lines. For my disability I need a copy/document holder that's mechanized in this manner so I can reach from my trackball mouse to the spacebar with a minimum of arm & shoulder movement. In 1988 I used one while working as a civil service clerk on a military base. I can't use the reg. kind of copy holder but have a huge amount of entries to my database that need to be done. I've been searching the internet for a long time & the only thing that comes close to what I need was found on a patent pending page but it's not being manufactured yet or may never be. Thank you.