Pattern calls for 3.75 mm needles but although yarn gives tension on same size, it had more stitches per centimetre so I went up to 4mm. Looking ok although I haven’t actually measured tension.

So I have finally finished a pattern I have had queued since 1985. Sorrento seems a suitable substitute for Patricia Roberts’ cotton boucle although I imagine the fabric that creates would be less airy than Sorrento.