I dunno if this applies but mine had a prob where my HU had power then when i turned on the parkers the power went out, long story short i created another earth and prob fixed.
Good luck though.
update on whats left
have you sold all the plastics from the gear surround up to the top of dash? (around climate control etc)
exhaust (would this fit a series 2) how much?
A/C compressor? how much?