We bought the trailer off ebay. Some say 36' some say 38'. I have the 2 door Ford dually to pull it. I hear this Whelen modified kit is still coming, and if it does, I'll have a unit. There is always something else you want.
I hope the following will be of interest to you. I don't know how to type the reference, but I can give you the path to it.
Lyle Willits model car shows pictures on Fotki
NNL East show 2016
Page 12
Pictures 368 to 376 ( or so )
Quite some models.