Thanks for the clarification. There isn't a database per se, however you can check the EASA Early Applications list
here and see if your ATO appears on that list. If it does, chances are you can do one course and one AOC with a dual qualified FIE as suggested by
portsharbourflyer - on reflection probably the easiest option unless you ask the CAA for clarification regarding licence issue dates and recognition of EASA training (which I still think is a little ambiguous!).
If you've never held a UK licence/medical the option to convert your medical isn't available, you'll need to undertake an initial Class 1 at a UK AeMC/Class 2 with a UK AME.