Lols...The mower is an earlier 35 Blumbly,series 2 I think going of the numbers,the first 2 series where Non Magister" so it cant help you either:(Im still looking for you so be patient,I have 20 guys looking for one at present so lets see what comes of it..If my coil didnt work I was gonna modify a coil to suit.Truthfully it would probaly run with the internall anyways,if there is enough power to go into the secondry theres enough power to run it,in part this system was a gimic and an assurance it could never fail under any circumstance,BUT it did....Regularly!!!!.just rewire it as you would any other mower,the wires you need are already there,so if it produces enough spark keep going,im sure it will be fine.And thankyou for the ring dimensions,saves me doing it blind.still cant find mine,it will turn up just when ive made the new one im sure. lols.