The Lambretta TV 175 series 1 wreck in my yard have proven itself useful again. I have just saved the bolt that thightens the headset to the steering column/fork. The bolt is special made for Lambrettas and has the Allen-system, much favoured by Innocenti. The point is that you have a fair chance to adjust the sprint in this cramped area, if necessary, without dismantling the whole headset.
Not even that helps if use a regular nut and bolt since a spanner or a socket wrench is way too big.
The bolt, nut and washer did come off, some 53 years after someone fitted them at the Innocenti factory.
Cleaned from grime and rust. I applied some spray paint as well.