Hi Hedge,
The reciprocal arrangement just covers the theory and cpl. The state of issue will be wherever you do the cpl. So if it's NAC the the UK will be the state of issue.
Even though the arrangement does'nt cover the class 1 medical, the CAA has always accepted an Irish one. However it had to be transferred to a UK version for the appropriate fee. The medical itself is the same and costs the same when currency conversion is taken into account.
Rgds
Willby