Top idea, Anne.
I've been up and down there a few times.
Wiggling through Blyth then going inland to cross two inlets, then back east again to the coast is a fiddle, and there's a couple of sharp banks.
On t'other hand, the track is reasonable as tracks go, and I was able to follow it the first time despite having no local knowledge.
NCN 1, as its number suggests, is a key cycle route, so there might be some support from Sustrans.
The battery company might be attracted to your idea, because a shiny new ferry would get them lots of positive (ho-ho) publicity.
There would certainly be more media interest in that than other worthy but dull projects such as a new community centre or planting a few trees.
You are realistic about your chances of success, but I've seen a few campaigns over the years which have got a good result, so it does sometimes happen.