WEBrick httpversion.rb and version.rb IPR copyright

Ruby-talk community,

My company, Aeroprise, would like to distribute WEBrick with our
commercial product. It includes two files, httpversion.rb and
version.rb, which say they are copyrighted to IPR (Internet Programming
with Ruby). We can’t find an express license associated with those files
but want to confirm we can redistribute them. Can anyone confirm that
the entire WEBrick library including httpversion.rb and version.rb can
be redistributed under the Ruby license?

Thanks,

-dan

Aeroprise, Inc.
dan at aeroprise dot com