Sorry Cliff, only a small thumb as I'm not a bowler... more a batsman and have dabbled a bit as a keeper... though SWMBO calls it hoarding.
Nearly got interested in bowls when I went off on a tangent threads in wood.... but got discouraged when I heard about thread chasing. Have you tried thread chasing?... anyone?
If your first cut is too short... Take the second cut from the longer end... LBD