It now seems to be working great. I moved the frog back a touch (it was flush with the mouth, but is now a 1/64th back from that). I’m getting whisper thin shavings now approx 2/3 of the width of the blade. The shavings are perfectly square and even thickness across their width so I’m wondering what the issue could be with the width of them. The blade itself looks to be square enough. I’m wondering if maybe I have the lever cap too tight and that might be changing the profile of the blade slightly? In a similar way to when you tighten up a Stanley scraper?
Anyway, I’ve made the wedges for the shooting board this afternoon and the finish is like glass. It’s just a shame that the are not flat and square though ;o). They will be by the time I’m finished, though, although by then they may well resemble a couple of match sticks, buried in a cubic metre of shavings!!