BAKELITE TELEPHONE HANDSET CRADLES
ALWAYS SNIFF YOUR CRADLES!

Bakelite phones can now be up to 90 years old and are made of plastic.  When plastic starts to break down it can be a disaster and in general only the handset rest, drawer fronts, cradles and plungers are affected on the GPO 100 and 200 pyramid style models.

The cradles will bend and eventually disintegrate to dust.  The drawer front plates just shrink and then break.  The plunger will sag.

Essential checks:-
Firstly smell the cradle and plunger - if you smell an acrid vinegar smell then they will require replacing.
Visually check the cradle - is there any discolouration on the ends - probably require replaceing.
Does the plunger stay down and not spring up - is this probably caused because the plunger is in contact with the handset rests - if it is then the cradles will need replacing.  Be careful though because sometimes the plunger sticks in the body due to grime - this can be cleaned easily - but if the plunger coloured with a blue residue then that is usually an indication of deteriorating cadles..

This handset rest below has started to deteriorate....... it will get worse!

This has an acrid smell and you can see discolouration at the bottom of the right hand upright

At the two points marked "X" you can see the slots are chamfered.
The edges should be straight.  The plungers should be able to move freely in this slot but they catch in the example above.