I've just bought a throttle slide for my Mk1 concentric and forgot to think about my lack of air valve, and air cable/lever. The one I bought is open on the air valve part rather blanked off as on my existing old throttle slide.
To use without air valve, cable & lever does it have to be blanked off ?
( in which case I'll have to decide whether to get the extra parts or get a blanked-off slide)
It wont make any difference and I dont think you will get a slide without provision to take an airslide. If there is a hole in the carb top to take a choke cable I would blank that off.
cheers Julian.