Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Does the light go out again above tickover/idle speed? If so, it is not unusual on a high mileage engine, also if it has new rings and shells it will run hot until properly run in. If the oil light comes on much above idle, STOP the engine and investigate further. Well done on getting your licence.
Hairy is on the right line here. Because you are running new rings, the engine will be running hotter than normal. But, sitting in traffic is not a good way to run a top end in. Have had this problem with 500's and 550's, it was the oil pressure switch.Have you done a oil pressure test ? Keep an eye on it
Easiest test is substitute the switch which is on the oil pump, or you can put an adaptor in there to actually check the pressure, but you cant put the cover back on with a pipe connected instead of the switch. Don't put a car switch in there as they work at a different pressure