SCHEIDMAYER und SOHNE KEYS

[ikehgl1]

Hi,
I have this piano made in the early 1920's.
I don't know whether the keys are ivory or plastic, though I don't think they had plastic in those days.
On the other hand the keys may have been replaced in later years with plastic ones.
Can anyone tell me what the keys are made of and also how to whiten them ?
Enclosed are photos with some keys showing cracks/
Thanks

[Barrie Heaton]

They look like Bakelite to me hydrogen peroxide little and often should make them white again.

[ikehgl1]

Thanks.

[ikehgl1]

Can you tell me which concentration, as they come in 3 - 30% strong ?

[Barrie Heaton]

3% Little and often it will soak into all the cracks and bleach them white but don't use a lot just a little each time.

Barrie