In theory yes it is possible. You’ll have to get the Windows 3.1 install disks and find the pbrush.ex_ (it might be mspaint.ex_ and expand the file using the expand.exe (should be on disk 1 or 2). Just stick expanded pbrush.exe (or mspaint.exe) someone on your hard drive (not in the Windows folders, create a separate folder for it) and see if it opens. It may work, or it may not. If it relies on old Windows 3.1 dll files those files may not exist or may have changes to much for the software to work.
You might want to check out some of the other shareware image software out there. Download.com has a bunch that you can try before you buy.
Paint.NET may work well for you, it is a free download with lots of features.
You might also try Virtual PC and install your windows 3.1 and use it that way.