Hi Nigel,
Roedean was originally described in English Mechanics with the rather less detailed description of construction that equally applies to Speedy also described in English Mechanics. ME subsequently acquired English Mechanics so then owned the copyright to Roedean and Speedy.
As stated above, ME reprinted the English Mechanics Roedean articles in recent years in 2011. Sadly the drawings especially the boiler were NOT updated though this was an ideal opportunity to do this.
In 35 years at this lark I have never seen a Roedean in steam on a track, and there are numerous complications with the middle cylinder valvegear and weighshafts and I would not consider Roedean by any stretch of the imagination to be a beginner's loco.
So I wish you all the best with a design that many have struggled with and many more simply avoided.
Cheers,
Julian