Thanks.
I've just had my '41 Chevy radiator re-cored at Tayside Radiators (£250) and have had to fit a new thermostat etc as it was cool all the time, showed how blocked up the old one was! They made a really nice job of it.
I'll get the Land Rover one done as well - probably a bit cheeper since it's a smaller core and will save any issues later, hopefully.
Cheers
D