Are you going to submit a CHIRP?
I've found that either Coventry or Birmingham are very helpful - Coventry in particular once gave me an excellent RIS (as it was then) when the weather-guesser's forecast proved incorrect.
Brize is never 'closed', but with the RAF's commitments and manning levels of today, the level of service outside normal hours is limited by controller workload. What frequency did you call them on - did you get any answer at all?