I was in similar situation but my UK JAA ATPL was valid although I hadn't done an IR in the UK for over 7 years. My UK medical was over 5 years expired. Getting it all sorted was a royal PITA. The CAA required me to get my HK licence certified (signed) and they requested a verification by the CAD which cost me and got lost in the CAA system for weeks. Much paperwork and forms required. From start to rating issue on my UK ATPL was 8 months. £5.5k on medicals, verifications and sims. Now I am trying to get an EASA ATPL on the basis of my UK one but its a similar story and some countries want the 14 exams.
It would have been so easy to keep all this going while employed and actively flying, but hindsight...