Can I sell a stock image taken on private property for which I don't have a property release but of which is not recognizable and has been edited? Nobody on the property has technically told me I couldn't take photos, then again, no one really knew I was. Additionally, I there are no trademarks or logos visible in the photos, the subject is clearly an object (not a room) and the photos have been edited. I guess I'm more curious to learn whether editing a photo enables me to sell stock without property releases.
You don't need a property release in order to sell the image as a stock photo. If a property release is required; it is required by the end user, not you.
With stock photography they are unlikely to accept an image w/o release even if the end use doesn't actually require it... part of that is because they don't know what the end use will be when accepting images, and as a general (over)protection policy. If the image is rather generic, they may accept it w/o a release.
The other implied part of your question is "was it legal for me to take, and now posses/sell, the picture?" I can't answer that definitively... but if you were not doing something you believe/knew to be illegal (against policy/etc) then it was/is probably fine.
You said the subject of your photo is clearly "an object." If that object is also a piece of creative work (i.e. a statue/painting) then your photo could be in violation of someone else's copyrights (varies by region and installation).