I machine shop could do a better job a lot quicker, I spent over a day doing it. Danny tried 2 machine shops but they would not do it because of libility problems.  That is the only tire we could find, I had to send to USA for mine, not avaiable here in Canada.I would find a small machine shop and ask them if they would do it, got to be someone around with a shop that does it for a hobby.  Give me your phone no. and I will call you and explane it to you better, cost me very little to call with my phone plan  . Just email me at  waynel@ns.sympatico.ca