Still waiting for the TAK Scope to arrive, but messing around today with the stock focuser alignment, trying to work out why one side of the collimation ring has so much tilt to get the laser centred on the secondary spot, I stumbled on the reason : One of the extension tubes (the one that I had the focuser mounted on) had paint on the anodised bevel surface where the focuser engages to the tube. The paint was the material used to coat the the inside of the extension tube and had run on one area of the bevelled surface creating a non-symetrical bevel. This probably would not have mattered if it was not the extension that I used to attach the focuser. The fix, I hope, was to sand the paint off the bevelled face. This allowed the tilt to be near equalised.
Anyone buying a GSO RC with these extension tubes should inspect the bevelled surface if using the stock focuser.
Have to wonder what the next surprise will be.