Still working on the detail from my photo of 64206 and I noted that there was a semicircle of rivets/bolt heads on the left side of the smokebox just above the handrail surrounding the bottom half of an oval patch.
The patch is made from some very thin brass shim that I bought from china via eBay several years ago. It’s just under 0.1mm thick
Next up I fitted the internal window frames and the associated rivets/bolt heads on the cab front.
Hopefully that should be it for the boiler/smokebox and external cab details until I start fitting the castings pipe runs etc.