Answers on a postcard please

This is the sculpture in Neil Ross Square in Ellon, not sure quite what it's supposed to be.....or who Neil Ross is/was come to think of it - anyone know?

Thankyou to Lainymac for the following Supplementary Info:-

"The sculpture in the square records the fact that on this site until fairly recently was the biggest tractor works in the north of Scotland. This sculpture was done by Frank Pottinger and represents various aspects of agriculture such as plough shares, rolling fields, parts of harvesters and so on. It is therefore the only link with a major employer in Ellon and indeed a significant feature of Ellon town centre"