Well I can't tell you anything about them but I have a 1979 Wisp 13 footer also! I bought it from a guy who converted it to a snowcone stand, he says it was a Dr Pepper concession trailer when he got it. I was planning on building a custom egg. It is currently gutted but it does have a full fiberglass belly pan and it very towable if anyone is interested . It is titled as a Wisp (manufacture ) and as utility trailer (model) . I have since bought a verrrry rare Pierce -Arrow 13' 7", 1936 built Travelodge that I will be restoreing instead of building the custom egg. Don't get excited I'm still pulling my 13' Scamp
to the hotrod shows , at least till the Pierce is finished ( that may be ten years at my current pace) . The Wisp has a couple inches more headroom than my scamp
and may be a couple inches wider. The overall construction is a top half and bottom half joined at the belt line. The door fits much better then my 75 Scamp
and having an enclosed belly pan seems like a better idea. The fender wells are open so tire/wheel acess is easier. If anyone wants it I'll take $750 USD.