There's plenty of long gone marques and historic models most of us have never heard of and that have some value for a very limited number of aficionados who keep it in the family.Historical status an contribution to value has a time window. Apart from truly unique history making vehicles, iconic vehicles, the "cooking models" rise, plateau in value then drop in value.
Paul Marx is right.
My 'Anne Elk' theory is that it correlates to people living with disposable income, capable of using the vehicle and having intimate knowledge being exposed to the subject vehicle in their youth. So we're talking say 50 years.
I can rattle off examples. Austin 7 anyone?
Laverda is going there slowly but surely, and probably faster than that due to legislation which will all but push them off the road in the 10 years to come.
Most bikers under 50 have no more heard of Laverda than Ceccato or MM.
So ride them, now.
Paul