Cleaning Glass on Old Tank

[Werbo]

Ok. Have an old 120 G that I am cleaning so I have a fresh start. Scrapped all the coraline off with a razor and washed to glass multiple times with vinegar, then Windex but there is still thin film that I cannot get off.
Has anybody had success cleaning an old tank and getting it as clean as new? How did you get the thin film off? Any ideas are appreciated.
Thanks, Tyler