It hardly has any tubes, just three that run across the top of the firebox of the water tube variety.
Haining's The "Countrymans Steam" Manual has sufficient drawings in it to make the boiler.
You could also use a vertical boiler rather than the horizontal of the Sufolk, there are a couple in teh MHS list and Harris's book is also worth looking at.
J
Edited By JasonB on 29/06/2013 20:04:28