Inside the mill - now a motor repair space. The hot water retting tanks (if that is indeed what they were) are behind the two walls at left and right and above them I was told are storage tanks for water. The space pictured is not large and would just have had the boiler and possibly other machinery associated with other services which were in adjacent timber framed buildings - now gone at this site. The stripping and bundling was in these timber buildings but the fibre left New Zealand in a raw state and not as processed goods. In the absence of further evidence I would guess that the fibre was dried on racks outside as was the practice world-wide, but I intend to dig up more.
http://www.panoramio.com/photo/74386052 shows a whole mill.
to see what a complete linen flax mill looked like from the air.