How do I get into my Electrolux 350 vacuum cleaner?

My Electrolux 350 vacuum cleaner has stopped working, and before junking it (it's over 20 years old, so I guess that spares are in short supply) I'd like to try to find out if it's a simple mend like a loose connection.

Bit I can't find out how to get into it. I've undone the only two screws I can find (under the filter near the cable entry and on-off switch) but still can't get the housing off. There's probably a simple trick - anyone here know what it is? Or have a repair manual?