I have little experience with the parts situation, but the only time when I needed a Marzocchi part, my Norwegian Gasgas importer got it within a couple of weeks.
Seals and bushings are readily available.
Regarding wear, I have now run the forks (as the rest of the bike) close to 160 hours. I haven't inspected the forks since my last seal / oil service at 120 hours (or thereabouts) but back then there was no wear to speak of. Perhaps the 2015 forks are better than the ones on your (slightly older) bike Jacobi?