Interesting question, hope someone has experience there.
I would think a radiator shop would have no problem building a Trans cooler into a radiator these days. Its pretty common, and parts to do so should exist? Of note, if I were to have a custom built unit, I would do some serious measurements and see if there is room for an additional core on the front side.

Vince

 

I've had both brass and aluminium radiators built for the various engine conversions I've done. Most shops can build anything that you want but I wouldn't believe there is anything special about the XK unit. Also my bet is they can fix the one you have . The easiest thing to do with most builders is to bring them the original unit and have them replicate it. As for the trans cooler I would believe it would be better to have it built in and the same size/volume as OEM. You may not have enough room for an external mount and it may interfere with the AC condenser.

 

I agree with JT, you will be better served to stick with the JLR design. These cars do not like to be under or over cooled and will throw DTC's in either case.

 

 

 

By saying "Over Cooled" I think he meant "Not within operating temperature" which would indeed throw codes. Coolant temps lower than expected (or 'optimum') is not a good thing. That's like removing the thermostat... it would probably never get the coolant up to operating temperature. Therefore codes.

Clever, I agree that Improved Cooling Capacity is a good thing. That would also include a properly operating thermostat.

 

Keep in mind that the plastic does serve a purpose.
Heat is forced to travel to the fins where there is air circulation.

 

I'd just fix it or replace with OEM and move on. There will be plenty of other items to spend money on now or later with the car.