As above!!
You can only request proof if you plead 'Not Guilty' which is fucked up, as that automatically increases your points/fine. So if you were speeding, there's no point in asking for it.
If I was you, had a clean license and was doing the speed I'd take it on the chin. Insurers pretty much ignore the first 3 points (and some ignore the first 6) as so many people have them they're now effectively 'devalued' and are no longer an indication of driving ability/safety.