internet archive: not sure how old you're talking but i have found a lot of older (and worldwide) cinema on there. they don’t have everything of course, but they’re free. i watched velvet goldmine and julian donkey boy on there and those are films that are less than 30 years old. but i also watched valley of the dolls there! the possibilities could be endless but i’ve only explored a small corner of the vast site. regardless, i love it. just google your film + internet archive and you may get a hit.
kanopy: not every library offers it and the content can vary depending on your library system as well, but it’s free with a library card. i’ve seen a lot of older films on there. some libraries offer hoopla, but not mine :( however if yours does that could also be a winner!
