Here is what most around here call a landplane. 
A 100 miles north of here they call them a float. 
They are 24 ft wide. Always used after deep breaking and around fields in the early fall before planting wheat on the turn rows. Here a link to an out fit that did build them. Don't know if they still do or not. http://www.loepkymfg.com/page/page/1666573.htm
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