For example: 100K? city traffic or motorway? quite a difference
Let's say: drive your 166 with normal care and gearboxproblems will not happen to you. As I can imagen that 7K would be at least for a complete new gearbox (or 2 )
As a dutch living in Finland, i can say that when it comes to cars and maintaining them it probably twice as costly to keep a car on the road as it is in Holland (or Belgium for that matter).
'68 Alfa Romeo Giulia 1300 TI '90 Alfa Romeo 33 1.3 -rip- '83 Alfa Romeo Sud 1.3 SC -rip-