OK I tried to get the ferrule off the old butt section to put onto a dowel, but couldn't get it, so am going to buy a new one - but don't know what size - the 1/4 inch dowel is 6.5 mm, but the 19/64 i.d. of the end of the present female is 7.5 - do I get the larger size and build up the 1/4" dowel? Or the smaller and will it fit the old male then?