If you do not get an answer, what I would do is to export the item as presently is as a CDP (just in case as back up), delete the # sign (and a few other characters one by one) in CM and see if this item still works correctly in Trainz.
Or I would ask the original creator per PM as he would know what the extra characters are for.
User names are after all user names, I often place a different character in front of the user name of my created items to find and see the item easy in CM. He could have just forgoten to alter the user name before upload to the DLS.
*Edit: when testing in game that is. Unless he uses a script referencing the username he uses for the item (which would be strange as it is the script class that is named usually with a different name) but this is easy to edit in the script, should he indeed do this.
Cheers
VinnyBarb