Whilst waiting for support, can anyone tell me what the replacement part is called for the connector to the front assembly? … and maybe a link to a video. 
Would this be the cause of sudden terrible overhangs on a model I have printed many times with no issues?
Molex 1.25mm and it powers the front toolhead LED and the part cooling fan, the latter will 100% affect overhang quality, which is the problem you got
from your 2 broken wires on the 6 pin molex, one is led power negative, other is power to the board negative (24v) so now neither your led nor your part cooling fan should function.
Check the last model picture on this link for the whole pinout for that connector
Bambu Lab P1 Series Toolhead Logo LED Mod by MicMac - MakerWorld