The radiator in the Toledo looked a bit marginal although in reality it didn't leak.
Neverthess, I took it to be rebuilt.
The guy at Walkers Radiators (Sough near Kelbrook, Lancashire) told me that the veins not only aided cooling but also supported the tubes in the core. If the radiator was left it would not only cool less well than intended but the tubes would swell without the support and eventually burst.
Well, it seemed fair enough to me so-
Here's the rebuilt radiator in place. I even painted the mounting brackets and fitted new hoses where I had them.
There that's much better - now a few more things need doing of course!