Yeah I understand what you're talking about!
But Most my bikes I got with less than a few hundred miles on them unless I got them for free, puchs, tomos, Italian, sachs too could be on a side of the house for 30-40 years and after you service the magneto and clean the carburetor they go, Actually derbi too but for me Maybe 150 puchs I either had or worked on they had the biggest percentage of working after sitting for 35-40 years out in the elements with a plastic bag over part of them maybe if I was lucky,
Belt drive French bikes, hobbits, Vespa and any other exposed belt drive moped nope!
30 years unprotected on the side of the house here in the rust belt they all were toast and needed full rebuild,
I did have a red Vespa grande for a short while that was between two garages with a half a tarp over it for 20 years that after carb cleaning ran good, with good pick up @ 31mph stock though the seat was so saturated from sitting where rain and snow collected even months afterwards your ass/pants would get wet,