£2 is a bargain, you did well there. Virtually any Kenwood Chef is salvageable, but yours doesn't appear to be in too bad a condition which helps from the get go. I think with very little additional outlay, and some time and elbow grease, you'll have a nice mixer that will last for many more years to come.
The only concern is the speed control, particularly if as you say it doesn't start until the knob has been turned beyond setting 3. It's not unusual for the speed control to fail on these due to age, due to one of more of the electronic components blowing. If this is the case, the mixer will still operate, but may run erratically, fail to go through all the speeds correctly, or kick out smoke. Sometimes this doesn't show up in initial testing, only when the mixer is given a good, hard run for the first time in years.
There are repair kits available to fix the speed control issue, and they're not expensive. They do require soldering however (which I cannot do, hence why I roped a mate into doing mine for me). It's a good idea to replace the feet at the same time, because if they have worn away, airflow through the base of the machine will be restricted, leading to overheating. Good idea to check the carbon brushes while you're at it too. The belt is inexpensive to replace, but if still in good condition can easily be re-tensioned simply by adjusting the motor mountings.
An eBay seller offering the repair kit (besides lots of other parts) is:
http://www.ebay.co.uk/itm/like/1213...3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108
Note they also offer a kit with carbon brushes and/or feet for only a little extra. I've used this seller before, and can recommend them personally.
Another source worth trying is:
http://www.kenwoodchefrepair.co.uk/Kenwood-Chef-A901-Repair-Kit
Note this seller offers to fit the kit for you at a cost of £25, inclusive of parts, if you don't feel confident doing it yourself.
Remember, your machine is a 901, NOT the later 901E. Although they both look the same, the speed control is where they differ.
Yet another option would be to upgrade your machine to take the current motor and speed control setup. This is more costly, but gives you a quieter, more powerful motor with greater speed control and a pulse function. Fitting this requires you to file out a small notch in the motor casting, hidden behind the speed control knob:
https://www.kenwoodchefrestore.co.uk/shop/kenwood-chef-motor-replacement-a901-upgrade-kit-part
Other than that, while you have the mixer apart, give everything a good scrub and polish and I think you'll be surprised at how well it turns out. The paintwork on yours looks to be in good condition, and the odd battle scar isn't always a bad thing because it shows the machine has been well loved through the years. They're not difficult to work on, and are easy to disassemble and put back together, but if you get stuck just say the word and I can give you some pointers.
