My parents campaigned for decriminalisation of homosexuality when I was a child (mum - Quaker), it's almost certainly amongst some of their non-fiction paperbacks boxed up in the loft at their house where my daughter now lives. When self isolating comes to an end I'll either retrieve the box myself or ask daughter's husband to go through it & see if it's there. Let's hope the paperbacks haven't rotted, they were pretty well packed and stored when parents moved to that house as they didn't want to cull just because they'd moved somewhere smaller, we too wanted to keep them.