That's unfortunate. I did an 'iTunes Mac' search in OldApps and it was listed in search links, but nothing actual except the message that iTunes is no longer available for Mac. I checked the Apple Support site as well, where there used to be a link to older app versions, but it's no longer there, or not that I can find.
You could try itunes.soft32.com, which has iTunes-Mac; or mac.filehorse.com, which has several Mac versions. I guess I should add "at your own risk".