No, you are correct in saying the radar display looked different in reality. Before 1.3 we could edit the PPI display, but so far now no one has been able to figure it out for 1.4 and 1.5.
To see what a real working SJ radar display looks like, check out these two pages. They are of the oldest working SJ radar set in existence, and it still works just like it did during the war:
http://www.usscobia.com/sj-1.html
http://www.usscobia.com/pics1.html