A very rare version was the 181 pick up. Only made (and probably only sold) in Mexico. The difference with a common 181/Thing was the lack of the canvas top. Instead the 181 pickup got a short hardtop and some wooden fencing in the back. It ain't no beauty but if it does the job...
I never saw a genuine surviving 181 pickup but I have the feeling this one is as good as it can get: