Dan, I have been doing a lot of editing of you sms files. What I have done is copied some of NALW and a couple of Diesel Wests (?) horns into the horn folder and then edit the sms files to point to the different horns and then renaming the sms file.
If you want, I will email them to you, along with a list of who used what and if you approve, I can upload them. Then others can use the sms files and edit the eng file to point to the right one. I will include a little text file that includes the alias line to be used in the eng file. Then all a person needs to do is copy and paste, no typing needed.
The new sounds are great. Been doing a lot of eng file editing.