Series rad in the standard place. Spal fan and flat shroud between rad and engine.
Similar to this, with some minor trimming.
Intercooler in front of the rad with some not great brackets holding it. Both cooler hoses under the expansion bottle. Oil cooler in front of the intercooler. It all...
Mine is a disco timing chest, defender manifolds, Skoda fabia RS intercooler, mocol oil cooler, battery over the relay, shuffled forward. Turner head and diesel Bob high power IP. I really like it. Got some upgrades coming, though.
Gauges are unreliable in accuracy, but good for a trend. If the lower hose is cold then it's probably okay, assuming the thermostat opens.
The voltage regulator in the dash needs an earth and is essential for gauge operation.
Run the engine for thirty seconds without the belts. See if the noise reoccurrs. If not then it's probably the water pump, could be the impeller coming loose.
I can recommend the Haynes manuals as a start point if you prefer to read. The actual factory manuals can also be found in line and from booksellers. Britannia restorations, Mike, from Canada, on YouTube, is excellent.
No series engine has a timing belt. Sounds like it could be a fan pulley coming loose and catching the cowl, or an alternator bearing. Check the tension on the fan belt.