After a year-or-so thinking about knitting these, I've finally produced a pair of Monkey socks.
The yarn is Lorna's Laces Shepherd Sock in colourway River. This yarn is fast becoming my favourite sock yarn as it is lovely to work with and washes very well (the Jaywalkers have been through several wash cycles now and don't seem any the worse for it). I knitted the pattern as written except for using heel stitch on the heel flap instead of plain stocking stitch.
They fit well once they're on but are a little tight going over the heel.
I'm currently working my way through a small pile of left-over sock yarn making squares for my blanket, then I'll be casting on another pair of socks (perhaps Nutkin or Vinnland) and maybe a summer sweater - probably Jaden from the latest Knitty...