Adrian
I would try and get a position in Supervision to start with explaining you would like to move onto estimating if possible, that way you have a grounding in what can actually be achieved by a Gang of Scaffolders and not some Uni Grad who has a Maths Degree and utilises CASE (Or whatever estimating programme they have been trained on) to spew out random quotations, it will also give you a feel for where the rates are at in your operational area and get you used to an office environment, believe me after I did 12 years on the tools it was most certainly a culture shock as you start at the bottom of the ladder again, hey, but at least your warm!!
Good Luck Mucker!