Running without a magneto

Hi

I have a Wolseley WD9 that I would like to run without a mag (i.e. use a coil).

Why?

The mag I have simply will not do the impulse thing. If anyone has a tip for me on how to resolve that I would keep with the mag.

I have a spare mag, but the mounting bracket (where is it goes onto the engine) is too big. So I thought to change the bracket with the other but for the life of me I cannot fathom how to strip the mounting bracket

Any and all help and guidance greatly appreciated