I have been moving my Great Britain collection from some old spring-back Windsor albums to newer albums. I was wondering if anyone can help me with more information on the following stamps...

Stamp 1 - I am not familiar with this overprint, is it a type of precancel? Is the purple cancel a revenue usage?
Stamp 2 - I am not familiar with this overprint, is it a type of precancel?
Stamp 3 - Is this a revenue stamp used as postage?
Thanks in advance for any input.
Don
APS #094826