You can take a 14 day free trial. Then there are different membership levels depending on what you want access to. They are all “cancel anytime”. You can pause membership for two months if you need a break.
If I understand you, you just want to plug the gap between when you grandfather was born and now. Is that right?
Had your brother looked at the 1921 census, electoral rolls, military records?
Can you be confident your brother’s research was accurate and as thorough as it could possibly be? You might just find that paying for membership might set you on a whole new avenue of research.
If you believe your family history is confined to the the UK, then you may only be looking at £13.99 to do whatever it is you need to do in six weeks.
It’s also possible that through Member Connect, you might discover members with similar research interests.