Based upon the description I am picturing the forend on ithaca crass guns prior to serial 25,000 or so. I have two of them. If I need to dig them out and take photos I will, but they are not handy. I would bet the gun has a foremd from an earlier Crass gun (mismatched) or possibly it was requested or built at the time of order to match a previous order or gun that was sent back for repair and/ or comparison.