Hey Pierre, that's a fantastic image.
It particularly caught my eye that you're using a Mewlon 180. I have one of these dedicated for planetary imaging. I hadn't dreamed it would be so effective for deep sky. The 0.5x focal reducer you're using, is it a homemade model? the Talkahashi one I think was only x0.85 or something similarly useless.
Is your webcam a Toucam or similar with the standard long exposure mod?
cheers,