Good afternoon Peter
No, I am unable to give exact dates. However......
During my first, or possibly my second, summer term ('60 or '61) there was a service to celebrate the centenery of The Wells House School in Gt Malvern Abbey. The event did not mean much to a 10 or 11 year old. But amongst us boys there was a certain amount of annoyance that the guest speaker - himself an old boy - was a Judge, possibly Stapleton(?), who had just punished Stirling Moss for speeding. Alternatively, the Abbey records might reveal a centenary service in June '60 or '61.
I don't know when it closed. The dates offered on Facebook seem rather later than I would expect. I rang the school in May '84 with a view to enrolling my new child, I can't recall the conversation, but I was not able to make the enrollment.
I think the bell in your photograph is the one used to wake us each morning when rung vigourously by Matron.