Autolusso do aftermarket Mocal cooler + hose kits for some models ~£250, though I don't know whether they can help with the 159.
Yeah, I did go down that route with them actually, enquiry form on their website, and follow up call. They don't have one for the 2.4 159, but the cooler for the 3.2 is jury-rigged into service with some custom pipework. The real saving isn't in the rad, that's about the same price, it's in the pipework, which is ~€40 and not €250 (seriously, for two pipes??). The challenge is that the mounting lugs are for an upright position, whereas the 159 mounts flat.
156 3.2 oil cooler (see the lugs at the bottom)
And the 159
TI have ordered me the AutoLusso kit, and will spend a few hours making a bracket match the mounting up properly.
They're having AutoLusso's modified intake manifold without swirl flaps, so while I'll be into them for €1,600 for this 'service', there's lots of preventative maintenance being done.
Timing belt, aux belt, water pump
oil cooler and pipework
new glow plugs (3 of existing ones were 1cm shorter than the others! don't believe the NGK website)
refurbished, spotless, swirl flap-less manifold
Poor Serena, I do love her, but loving an Alfa can be a pricey business. This service cost about the same as my first car (1.7 Puma Black Edition)!.