I am modeling the midwest (KCS Kansas City Area) in the early 1980s.  I have several 60' MDC flat cars (HO scale) which I would like to add farm equipment or construction equipment as loads.  I subscribe to the "Good Enough" philosophy, so I would prefer modifying toys such as those found at Walmart, rather than spend $30-$60  a piece for scale models.  I have found some nice near HO scale 1/87 toys of both farm tractors and construction equipment, however I don't know what models would be appropriate for my era.  I don't want a flat car running on my 1980's layout with equipment produced in 2000.