I appreciate that this sort of thing shouldn't happen, but focus on the outcome you want - which I would think is to have you car working properly as quickly as possible. So how about this:
1. Drain the coolant and remove the hose
2. Take the hose to a decent motor factor and get a replacement. Easiest would be a motorsports specialist who could make you up something from silicone sections
snip
In my experience, proper motor factors are enormously helpful to owners of Morgans. I've been let loose in stores on many occasions. Chances are the hose is the same as something quite common, the problem is finding out what it is.
Even Halfords have been helpful when I was after bits for the three wheeler, made a lad's day when they had a battery for it although I kept quiet on the fact a few years previously I'd adapted it to take the same battery as the 4/4.
