Good morning all, can anyone help?

I recently had a knackered battery (dead cell) so I changed it, the battery I replaced it with had the terminals on the wrong side and without checking I reversed the polarity (dumb I know) and connected positive to negative and negative to positive.

Having replaced the battery with the correct one I realised I blown the fusible links on the top of the battery, I bought a replacement unit (OEM 8571A026) and installed it, however I have a couple of outstanding electrical issues.

No central locking (it had worked perfectly beforehand)

No power to the stereo or certain dashboard functions

I get what sounds like a handbrake alarm when I initially set of that stops after about 10 meters and comes back every time I slow down.

I have checked all the fuses and they are fine but I still cannot figure out what is wrong.

It feels like I have missed a fusible link but I cannot find it.

I spoke to a mechanic who suggested one of two things, 1. Transit fuse had blown - I have checked all fuses and cannot find any that are blown or 2. The ETACS unit has been damaged.

Any help would be gratefully received as I am know where near a main dealer.