We'll after reading about everyone's problems and ideas on how to remove the flies I put this off for months worrying about getting those little screws out without stripping them or dropping one. Well today I got motivated and read the flies out post and gave it ago. Don't know what all the worry is as they came out easy as no prewarming no new no.2 magnetised Phillips head just my old trusty tool box and within 40 minutes done.
Now for a test run and see what difference it really makes