Here are a couple of quick pics - let me know if you need cleaner ones. I also noticed a skirt around the base in the above drawing. I dont think mine has this - except at the rear.
Dirty little devil isn't it? I note a clip over the top of the carby too, as well as the press-in primer button. The filter holder appears different too.
Stationary smile

[Linked Image]
[Linked Image]

I used to be indecisive. Now I'm not so sure.