Here is an example of the older aluminum sided trailer... Evokes similarities to a Freuhauf van...

For those collectors that follow Tonkin Replicas Signature Series trailers, there have been 5 different 48' trailers used in the last 5 years (the oldest tool being the one above). 3 of the trailers are from the same trailer family as the Club Car truck listed in this blog earlier- that trailer was an all metal version that yielded a 3 pound truck and trailer (roughly). Built at a time when zinc was $800 / ton... and gasoline was $1.10 / gallon. That same trailer, however, had a plastic slide option for the middle panel, plus a full plastic version. The only full plastic version of that trailer done as a production run, however, was for Chevron. I will look for a photo later. The final trailer is the current 48' trailer built 2 years ago to be a more efficient trailer. A blend between the extremely heavy but inefficient trailer group and the older aluminum trailer which still operates but represents older die-cast technology.

Tonkin Replicas classifies these trailers in order which these 48' trailers were built:

I. Aluminum Trailer
II. KL Trailer Family (3 versions)
III. Single Modern 48' Trailer

Due to the decline in real 48' trailers on the road, the most common place to find the current 48' is on Rocky Mountain double or Turnpike doubles combinations...