Check with BCM ( Bisson Custom Mufflers / Canada). They offer several clamp on mufflers. I have had great luck using the Sport and low DB Sport. One other option is to tap the case on your Webra. The ones I have that are tapped use the OS #744 muffler bolt pattern. You might also look at some older Hobby Shop like Sheldons Hobbies and catch some old stock. That auction site is another good place to find a original clamp on.