Keep away from domestic, with your experience you'll be bored after a couple of weeks.

I'm Electrical, Mechanical, Control Systems, Plumbing, Heating, Gas Safe registered and a load more skills aquired over the years, I'm not ex forces.

3 of my work collegues doing the same job are ex forces.
1 Electrical Tiff - Lack
1 Mechanical Tiff - Kirby
1 RAF Weapons technician

All retrained to get Corgi, now Gassafe registration about 7 years ago all of us do Commercial Building Services Maintenance work.

Over the years I've also come across Commercial Refrig Engineers who retrained when leaving the Navy.

Hydraulics / Pneumatics will help you into Refrig.
.