I recently acquired a loom that has no brake release from sitting position. I want to fix that. Anyone else have this problem? There is no identifier on the loom but it does not seem homemade. 



Without seeing a picture of your loom, it's very hard to suggest a fix.  Lots of looms require getting up to advance the warp.  One solution is to use live weight tension.  You wrap a cord three times around the beam, with a heavy (~20#) weight on the tension side, and a smaller weight on the other side.  It can take some experimentation to get the cord and weights right.  A very smooth, slick cord doesn't work.