No, is over of isn't a valid construction. When something's finished, is over stands on its own: The meeting is over. It can still take time expressions without any preposition: The meeting is over by five or The exams will be over next week.
Examples:
- Talking about something already ended: The film was over when we arrived.
- Pointing to when the ending happens: The exams will be over next week.
- A sentence that continues past the verb with timing: The arguing is over with before the holidays. Informally, many speakers add with here, so over with is an optional variant rather than a form you must reach for whenever timing follows. The arguing is over before the holidays also works.
The decision-changing point: over with is an informal choice, common in speech, and it only applies when a phrase follows over. If nothing follows, is over alone is the natural form. Never write over of in this finished sense; if a preposition does follow over, it's with: The audit is over with at last.
Never write over of in this finished sense. If a preposition follows over, it's with: The audit is over with at last. Any of would belong to another word, not to over itself.
Wording by situation
Closing a message about something finished? Is over stands alone with nothing after it. The meeting is over, so you can head home now. Adding of, as in is over of, reads as an error to any fluent reader.
If you add a phrase after over, is over is still fully correct, and a timing phrase doesn't change that: The arguing is over before the holidays. For an informal alternative you can extend it to over with, as in The arguing is over with before the holidays. When you use that extended form, keep the preposition as with, never of, in this finished sense.
For a report or update, contrast a settled matter with one still going. The audit is over with at last, but the paperwork isn't finished yet. Only the settled part takes with; the unfinished part needs a word like finished or ongoing.
One related but different pattern takes a noun directly: be over something means you've recovered from it. I think she's over the flu now. That object belongs right after over, with no of in between.
When over describes movement or position, it takes its own object, as in He ran over the bridge. There, over means across or above, not finished, and any of in such a sentence belongs to another word, not to over itself. In the finished sense the picture is different: only is over or is over with is possible, and of never follows the verb. So The meeting is over works, and The meeting is over with works when a timing phrase follows, but you wouldn't write is over of in either pattern.
Why the preposition doesn't transfer: the idiom get something over with is about doing an unpleasant task so you can stop worrying about it, and it always takes an object naming that task. Let's get the dentist visit over with this week. That's an action you complete, not something already done, so the finished forms is over and is over with won't work in its place, and is can't replace the action verb in that pattern either.