Can I upload addons that are impossible to find or download?

I have been reviewing my old computer and found several paks of both the Hispanic simutrans page and the international simutrans forum thread in "brainstorming"
as for example the asphalt highway of 250 km / H

4 types of citycars

or the vehicle.Kenworth_KC104B or vehicle.Kentworth KS50

and others that I have to see
yes, giving credit to those people who did the addons
but can I upload it??
