Having read your second post, I would say as per Mike in post#2.
Neither you or your brother are boaters, sorry if a bit harsh but you both have lives that are shore based.
As to spending lots of money (thousands) that will not be recoverable because of a guilt is definitely not the way to go.
Do not under estimate the cost (thousands) and the time (years) that it will take to sort the boat.
The only reason to keep the boat is if you or your brother are absolutely, positively sure you want to live on the canals.
If you decide to keep it, remember the ongoing costs, licence, insurance and mooring, probably over £3,000 per annum (total) and that is before you use it.
Then there are maintenance/repair costs.
That is £5,000 per annum in total.