The heat was not circulating around the workshop and because the stove is close to the door and window it seemed like the majority of the heat being generated simply went straight outside. The large lump of Wadkin cast iron simply did not have enough heat getting to it to warm it up and yes ice cold cast iron + warm damp air = condensation.

We got a stove top fan to circulate the warm air, powered by the heat from the stove this little thing is nothing short of a miracle, the result is that the heat is now circulated around the workshop and the lump of cast iron can soak up enough heat to avoid the condensation issue. 

Added to that we were able to use all of the large quantity of packaging that came with the flue components to create some secondary glazing on the door and windows, not pretty but it certainly works as you could feel the place warm up as we stapled it into place.

At any rate we are now really warm and, fingers crossed, have seen off the condensation issues.

The fan we bought is here, price was good and delivery was within 24 hours.