The string catching on the knob is an easy fix. Just cut a triangle piece of wood that mounts under and extends just past the end of the bolt. Sand and round the edges and and glue or screw it in place. If you have a router and can sink the triangle a 1/16 of an inch even better. I had the same problem on my stitching pony and it was well worth doing. That is a nice looking pony and you will really get a lot of use out of it.