Mps 6 Help with switching immobilizer ecu Bcu everything. Won't start.

Hey all,

Recently bought a mps 6.
3 weeks ago it was immersed in salty floodwater to top edge of front seats, as I just bought it it was unregistered and uninsured.
I've bought a second mps6 shell for the electronics and interior bits.

Used over 5 cans of wd40 on loom plugs and Replaced all the boxes I can find but I can't start the engine and the immobiliser light is showing an error(flashing rapidly when you turn key to on, then after 1 min it flashes the error code 1 flash break 5 flashes).

That error code according to the workshop manual means wrong transponder code Id from key.

I am not sure what I've done wrong as all the components and the key transponder have been taken from the donor car.

I've done my research as best I can, the gg model has the immobiliser that doesn't require the instrument cluster swapped, nor do I have it to try as it was not in the donor car.

Stuff I've replaced...

Passenger side:
Bcu under fuse box on left
Ecu and black box under false floor
Wireless receiver behind glove box

Center:
Control box on top of hump

Drivers side:
Transponder on key
Coil antenna (not nessary but getting desperate)
Amp under driver seat

Only option I can think is tow it to a Mazda dealer to reprogram the immobiliser to accept the keys.

Questions
1. Did I miss anything in the switch - is there some other box that is to do with the immobiliser?
2.Anyone know if someone from mazda/authorised mechanic can come to my home with appropriate software/hardware to recode/fix immobiliser?

Thanks from an almost mps 6 owner.
Luke

Maybe important info, I first tried the pcm/ecm/ecu on its own, then switched the bcu... maybe that has caused an error code to stick around even after I've switched all components...

Anyone that can answer anything, even if it is just to confirm that I have indeed move all the immobiliser relayed components would be greatly appreciated.

Luke