Release Catch Problem

That is really old, focus your search in the UK and auction sites selling second hand stuff.

Late but I had the same problem and fixed it on me tod so maybe it will help someone else. There are two stages of closing, it will shut at around 6 o clock but it's locked when it's around 8 o clock (it should click into this same position when fully open) I fixed mine by pushing it down harder than I was doing. If it won't lock after this then a spring is borked.

hi the lock nut on the shaft may have been loose allowing the shaft to screw into the dough hook you hve to unscrew the hook out of the shaft then unwind the nut down so you can release the shaft. other problems can occur if the retaining clip has unseated and jammed itself into the planet hub. this is more difficult and a kenwood agent would be consulted see www.kenwood.co.uk for nearest agent.

Can't refer you to a dealer there but it is likely that only the motor's brushes need to be replaced. This isn't a difficult DIY job and the brushes shouldn't cost more than ~ $20 US.
You could also remove the housing covering the motor and see if the commutator is visible. This is a segmented copper cylinder and shouldn't be completely blackened although some signs of black is normal. The brushes ride on this cylinder and if the brushes have become too short, it can cause arcing and smoke. Clean that surface before installing new brushes and they too may smoke and cause rough running until they are worn in. The brushes can be had many places so you will have to choose one convenient to you:
Kenwood Chef Brushes

I got service manual if any one want it.seamusria-at hotmail.com for kenwood Kenwood chef model A.701A.

If the attachments that you are talking about are the dough hook and the whip, then the red lever is not used to put them in or take them out. The red lever releases the plastic housing on the end of the mixer, which then exposes the mounting hole for the major attachments such as the grinder, sausage maker, etc. You push the red plastic lever, then gently pull off the plastic end of the mixer. It should come off with absolutely no force. Then insert your food grinder or other attachment with the red lever held back. Once the cog on the grinder is aligned with the fitting inside the hole, release the red lever so that the recessed hole on the grinder will become engaged. The Kitchenaid classic stand mixer and the Viking stand mixer have essentially the same set up.

Here's how to fix the stuck implement problem:

The implements each have adjustable heights. to adjust the height you need to loosen the bolt at the top with a 14mm spanner. If the bolt was loose when it was being used then it can get too short and not leave enough clearance between the bolt and the machine in order to push up and turn to release the implement. If this happens take the open ended spanner, grasp the implement and rotate the spanner clockwise (when looking up at the machine from below. Once the nut is loose rotate the implement until there is enough clearance to remove it normally.

To open take off the top and open the three screws. Use light grease.