For any 456, I would add (in addition to John's 550 list) the low pressures power steering line to the tank in the RF corner. It is not uncommon to see fluid leaking through the actual hose. In addition, inspection of the rear self-leveling units, hoses and hydraulic dampers would be prudent.
Enclosed is the final version of a PPI Checklist I recently developed. Actually, a more accurate description is guidance, advice, and wisdom I gathered from experts here on the forum (Taz, John, Dave, and others).
Thanks to everyone, your expertise and experience helped me find, evaluate, select, negotiate for, and acquire a 456M GTA.
She should arrive tomorrow, so I'll post photos and info this weekend.