As far as I know, the only requirements are:
- Five hours total including (I think) three hours cross-country
- Five solo takeoffs and landings (landings to a full stop; touch and gos are not permitted)
There is no exam, and I am fairly sure that there is no time limit within which you've got to do the above. The fact that your flight school seems to work to a syllabus is very good but is not a legal requirement.
So legally all you've got to do is 1.5 hour flying, to include the 5 solo stop-and-gos. And the obvious paperwork and CAA fees.
Whether that is sufficient for you to feel safe, and for the club/school to rent you a plane is a different matter of course. If you haven't flown at night for over five years it might be wise to simply forget about the 3.5 hours you have right now and start all over again anyway.