I wasn't sure if I should sell this but people are collecting focusing loupes now and this is a model I have never seen before, so here's your chance for something different.  The bakelite base slides over the ground glass hopefully without marking it, there is an adjustment with a locking nut that hasn't been moved in 70+ years and I'm not putting it in a vise to try to free it up.  It works perfectly as-is.  There is some internal dust but otherwise the glass is good.