A very interesting offer......I've been looking for used Dansk muffler for a while.
You mention that it has been modified. How has it been modified and what effect does it have on the exhaust sound? Where are the port holes located? I can't tell from the picture you've posted.
Could you post additional pictures of the underside and back of the muffler?
The sound with the Dansk on my car was slightly louder than stock. The mod. gave it a deeper tone at low RPM and just a little louder at higher speeds. It's difficult to compare because my car has headers and sport cats so if it was stock I'm sure the results would be different. The Dansk is a very well built muffler as you can see from the photos. There are a bunch of you tube clips to hear.