I'll try & help. Came here 3 years ago with Aus ATPL Dash 8 experience & 2800hr total(I think approx).
I had to do everything except morse in the theory & for flying I had to do Training to standard & test in the GFT(Aus CPL equivilent)& CPL/IR.
UK CAA don't make it easy for you but they are fair in that they tell whats required & don't shift the goal posts.
Difficult move & definitely expensive!