Hello Frank - not good news I'm afraid. I spent an hour and a half walking round the graveyard inspecting all the headstone for names. No Jackson's. Many graves were unmarked - no headstone and in many cases, no kerbstones either. Some, that weren't that old were unreadable (sad to say because they were poor quality - could tell, as they were same material/design). A few are "hidden" or "buried" behind or under scrub or trees and can't be viewed unless the scrub, etc cleared. We have done that in the past butit does take hours! David is your best bet. He can tell where any grave is and if it's not "hidden", show you where it is. Truly! I've witnessed one plot being discovered and another (under a large amount of scrub and trees)that had friend Mike's baby sister in from the 1940s. So there is hope! If you contact David and you can't get to the church, I could go and take photos if we can get to them. The areas that your graves -40s & 70s,- are in mostly open areas. Sorry I wsn't able to find them Frank.
The church is redundant but open every day 10-3pm by the "Friends of All Saints" who love and look after it. twice a year they have a "gardening day" where they try to remove scrub and rogue trees. The council cuts the grass 4 times a year. SO - the church and graveyard is loved. Most of the "friends" are female and retired! Surprise, surprise!
Regards
Denise