Phil Smith might be able to help. He might have screens,too.
TED....

 

Dead? can you turn the armature, have you checked braids, connection- resoldered..or are the magnets gone? In painting, test before going at it..I had those cars back new and seem to recall the plastic was soft..now will be brittle and thick with dust, finger grease..so make sure to prep and prime

 

Jallu - these are first-generation Airfix slotcars from about 1963. Those old Airfix motors are very simple. I assume the motors turn but do not run if you put power to the terminals?
If you look at the front end where the braid wires are fixed, you will see the flat copper springs which hold the contact brushes. Older versions like yours probably have wire springs. Later ones were flat copper springs.
If the springs are missing, that will be your problem.
If the springs are there, carefully lift them slightly. The motor brushes are underneath. They should be little cylinders 1mm diameter and 3mm long. They should slide in and out freely and press against the flat contact piece (the commutator) on the end of the rotating part (the armature). They get very dirty and sometimes oily. If yours are stuck or dirty, take them out and clean them as this might be your problem.
(Later versions of these Airfix cars had normal Mabuchi/S-can motors fitted, as well as windscreens and chrome parts. There’s plenty of room in the shell for them if you decide to go that way, but you’ll need to do some work to make a mounting for them.)
It looks like the green Lotus might have the Ferrari wheels fitted, or else have been repaired with red plastic. The Lotus should have green, web-spoke wheels and the Ferrari should have red, wire-pattern wheels. All the wheels and axles can be changed between the cars. The silver chrome wheels are from a later car.
The cars are made of polystyrene like a normal Airfix static kit. They were easy to break even when new, but easy to repair with model-kit glue, and easy to paint.
If you use Scalextric track, you may find the guide pins on these Airfix cars are too wide and need to be ground down to fit the slot. There is no problem with the grey Airfix track if your set has that. You’ll find the cars run very nicely, with good handling.
Please post an update, and good luck!
Mike

 

I agree with the above, usually these motors run very well after some cleaning, oiling and retensioning the brush springs. Furthermore they are perfect for the handling characteristics of these cars: a more modern motor is not easy to fit and probably will make the cars more difficult/unpleasant to drive. So, in case one the motors eventually refuses to run, it is probably better to replace it with another of the same tipe, as they are very common.

These cars are early versions and didn't come with windscreens. Lotus in green and with unbroken exhausts aren't seen so often, so I would be advisable just cleaning/polising the body instead of painting it, but of course it's your choice; once repaired, race it with care...

 

I had a secondhand Airfix set with the Ferrari and Lotus when I was young and the motors in mine had so much endfloat on the armature that the brushes couldn't maintain contact with the commutator. I could probably sort it out now but when you are 8 or 9 years old these problems seem unsolvable.

 

Looks like modern HO open can motors would fit - same as Ninco Karts.

 

42Redcat and House are spot on, both are early first version cars and do not have windscreens and the wheels should be the same colour as the bodies. One of the weakest parts are the wheels so lots of cars end up with replacement wheels which in most cases are chromed. For the same reason people tend to mix and watch wheels so a lot of cars end up with the wrong wheels. Even under the chrome plate the wheels are the same colour as the bodies. The bodies as moulded in styrene just like the Airfix kits so if you want to paint them and model kit paint will work.

The Lotus is missing the the steering wheel and looks like the seat, also the steering unit is fitted backward as the moving pin should be at the front. The Ferrari is missing the roll bar.

Parts come up on ebay all the time but the cheapest way can be to buy a working wreaker or two.

 

Further to the point about body colour vs chrome wheels, if you need to dechrome parts I've recently discovered that a cheapo Ebay ultrasonic cleaner takes off Scalextric plastic chrome very nicely (or not nicely if all you wanted to do was clean the part). I assume it would have a similar effect on Airfix's equivalent.