It's not only the 166's. It is hard to come by a well kept 156 V6 now...much easier to find a good 156 GTA...and Alfa sold over 3000 156 V6's in the UK...
Expensive to run, and, unlike the GTA...pretty much worthless...so why waste money on looking after it?
(That is not my opinion, but the general way of economics)
I saw the same argument in a Shed of the Week post against a 166 shed - Scorn poured on the idea of spending another 600 quid on belts and fluids - "just hope for the best and buy another of it goes bang"
I'm giving mine a 1000 mile "shake down" see what problems show themselves before spending the £600 on the belt.
So far so good, only niggle is the weak synchro on 3rd. I don't think there's anything wrong with the clutch, it's a bit low and heavy (compared to my E36, Alhambra, Mrs Citroen Sponge etc) but there's no dragging and now it's had regular use the gearchange is good and light.
The ICS screen is a bit dim (can't read it in sunlight), but I intend to practice on a supposedly dead one I picked up for 99p before going near my nearly-perfectly-working one.
Reading the thing about the sills I'll dust off my waxoyler from 1992 (GT6 restoration) and get oozing..