Our Vandercook No. 4 does not stay in trip. When printing, the operator has to hold down the trip to keep it in place. In comparing it to our other No. 4, the trip mechanism is still in place, but the trip bar connected to the handle has a lot of play; there is no tension to keep the lever raised to rotate the shaft connected to the rear trip wedge and I can’t get a good vantage point to see what, if anything, is missing or broken. Any insight?