Finally rebuilt. I took it down the road to check all the fine tuning was complete .... and ended up riding 30 miles.
How can a bike so small feel so good?
(Apologies for the poor phone photos)
I figure even though it is 16", the long seat post and stem help the position. Even the hand space on the bars is set up small so my hands only just fit between the bar ends and brake levers, but all in all it creates a bike that just feels really agile.
Having finally taken it off-road, my opinion is that it is a great, sharp frame to ride and feels like your power is transferred very easily and smoothly. It's pretty firm to ride though, even with decent sized tyres and when I got home tonight I certainly felt a bit of buzz in my hands and feet. The braking feels really sharp too, with the new rims and replacement Ritchey pads.
Despite me probably looking ludicrous on such a small bike and the fact I need to reduce the number of bikes I have, I will be keeping this awhile yet as it's probably my most favoured bike to ride off-road at the moment.