Re restrictions on which year groups could come to school, here is an extract from the latest DfE guidance.
Welcoming children back to school
When we made the decision to ask schools to open only to a small number of children, this was done with the aim of reducing transmission of coronavirus (COVID-19), to protect the NHS and save lives. As the situation improved, we began to consider how we could bring more children and young people back into schools, and supported primary schools to do so from 1 June, focusing on some year groups being educated in small ‘bubbles’, and secondary schools from 15 June, with year 10 and 12 spending some time in school in small groups, with public health risk reduction measures in place. Since 15 June, primary schools have also had flexibility to bring back other pupils where they have space to do so.
From
www.gov.uk/government/publications/actions-for-schools-during-the-coronavirus-outbreak/guidance-for-full-opening-schools
Unfortunately they don't keep or highlight changes, so unless you downloaded or printed the original, it is not possible to show when the changes happened. As a serving headteacher, though, I can confirm that originally we were directed to close to all except Key Worker children, then to take Nursery, Reception, Year 1 and Year 6 as best we were able from June 1st, and, despite Gavin Williamson's gushing statements about welcoming more back, we were directly forbidden from doing so until 15th June. I have an e-mail from the DfE confirming that until the revised guidance was published, I could not take more back. It was immensely frustrating, because my school was able to welcome more back, and parents were getting cross as they had "seen it on the news" but I was preventing it.