Interesting debate. Perhaps the way forward is European Classic mechanics, rather than specialising on just the Laverdas. Not ideal but covering all the old Italian marques might be enough to make a viable business.
Regarding young folks coming in to the sport, I think we old timers have to be careful. I see a lot of gate-keeping and knocking the choices of younger riders. If they want to make bobbers with brown seats out of 1980s Hondas, good luck to them. They are appreciating the older bikes and a percentage will get drawn in to 'proper' classic bikes over time. Our pastime needs the new blood.
Difficult enough to cater for just one marque, holding mostly dead stock for a half dozen defunct marques is financial suicide. There's lots of stuff that fits all sorts of bikes still available and being offered by quite a few and will probably remain so for some time to come, at least as long as the clonkers remain on the road and are worn out. Sure, there's money in re-manufacturing, but the costs are rising daily... at some point even repro parts will be simply too expensive to flog on. It's the special bits that are the problem, stuff that sells an item per year, but only makes sense if you make 100.
Accumulating expertise to offer proper advice for one marque takes decades, don't think there are a dozen people on the planet that could offer in-depth advice equally on Moto Guzzi, Ducati, Laverda, Bianchi, Moto Morini, MV Agusta, Gilera, Mondial, Parilla, etc, etc. One would need to amass an incredible wealth of information, or find people with that knowledge, but, where are they? Old, retired, dead...
A good example of this is the UK company Feked. They cater for many british marques, mainly those that shared proprietry parts across their ranges. They offer mostly consumables, their repros come mainly from Taiwan and India, with obviously a few from the UK cottage industry. Even a few OEM bits such as Doherty levers and twistgrips, which is truely amazing. But don't ask for advice such as "will this X fit my YZ?" That's where one-marque clubs chime in.
"Classic" biking as we know it will die a sad, slow death, which, imho cannnot be stopped. Our bikes will eventually land in a museum or a crusher, with maybe a few surviving as living room show pieces, not turning a wheel, ever again (see Ferarri GTO, Lambo Miura, etc for fear of breaking something irreplaceable). The current fad of wrapping rusty exhaust pipes of derelict Honda CB350s will fade as soon as the hipsters find something new they can "re-invent". The entire hipster movement will eventually fade, the next might start re-juvenating old Nokias and proclaiming them the hottest shit around. Oh, they're already doing that... ? History repeats itself, rockers, mods, hippies, all going the way of the Dodo, except for a few dozen die-hards holding on to the last, thin straw.
Motorcycles have evolved from (necessary) personal transport to (optional) recreational toy. When interest wanes, they will disappear, simply no longer needed. Although bikes may be a solution to crowded city traffic, the necessary long-term push towards public transport will eventually push them out of the picture as well. Will probably take another 50-odd years or so, so it shouldn't be worrying too many here.
piet
