There may be the rights to do them, as copyrights vary, sometimes you think the copyright is done, but it might be renewed by family members or companies.
I'd rather play safe, than sorry.
Don't let ANYONE tell you there is a certain percentage that you can change or copy, as that just is not so. Noone can assign or calculate a percentage of change. I have seen people sued successfully when a subject was similar but the rendering was changed almost completely.
I am sure that people are inspired by things they see all the time in print or on the web, etc. and do work from these images somewhat.
The entire thing is to be aware that copying to any degree should be avoided.
Sorry I didn't get back sooner with you. I was busy at work, and had computer issues once I got home.
For a full run down on copyright issues - use the link in announcements. There is some very good information there.
~Jillian
~Jillian
artist, Jillian Crider
... google me!