The Frequency card dished out with the charts these days is quite handy yes. Ed 29 was the last one I got.
On the back of it for Abingdon it has Benson Zone (120.90) listed as the NATSU to check for activity, and if unable to establish contact on that frequency London Information can also pass advice on our frequency and whether the airfield is operational.
122.10 is the contact frequency at Abingdon for weekends and when Notams are active for the VGS but Para dropping can use other frequencies if they have an ATCO or if they are under control from Bzn, so it is the safest option to check with Benson, Brize or London if you are passing and not sure.
Failing that of course, it does state even on that card that pilots are advised to assume the zone is ACTIVE if no information can be obtained.
But as you have that card, I'm sure you were aware of that already.