duetto66,
First, Welcome to the Pelican 911 Forum
You will find a lot of help here.
The ’69 911 wiring is unique and not remotely similar to prior or subsequent years.
… Well, remotely.
Other than the connectors, Porsche wiring is relatively immune from damage by water.
There are many other parts of the car (including chassis) that are more susceptible to damage.
Where the harness is wrapped, it can be unwrapped, cleaned, dried and rewrapped.
I think Porsche will make you a new harness but that might take into the next decade and rival the budget of some small countries.
Having your existing harness,
you can manufacture a new one.
I understand the wire and connectors are available.
There are a number of ’69 owners that might cooperate in a mutual effort.
Tell us more about the flood damage.
Interior chassis cavities are a concern.
You may have the opportunity to take your 911 down to the chassis and repair it so it will never rust (again).
Best,
Grady