Great, thanks.
Some remarks:
- it's often useful to indicate in which directory the new files should go (i.e. $(lazarusdir)\components\ideintf)
- Typo: you spelled the filenames DBGrigColumns... instead of DBGfid. Also, the rest of the files there use lowercase, so probably best to use the same convention
- your indentation in the patch (TDBGridColumnsPropertyEditor = class (TCollectionPropertyEditor)) does not match the rest of the code
- typo in function name, some vertical linespace.
Minor stuff really.... but the kind of stuff I can check easily

No idea about the actual content though, so no comments there

I took the liberty of creating a new patch and renaming the files. If ok, could you upload them to the issue tracker?
Thanks a lot