LP12 - identifying Cirkus bearing

I need to know how to identify the Cirkus bearing upgrade on an LP12. Is it possible by looking at it??? Trying to buy one, but the seller is not sure if it has it or not. The serial number is just over 80000...thanks
It appears the Cirkus was added starting in 1993 with serial number 90,582.

The Cirkus bearing is flanged out at a 45 degree angle as it mates to the bottom of the subchassis. The original bearing is not. I think I have a picture of both kicking around somewhere. The color of the bearing well is not relevant. You might also want to check the pink fish media site, which, being a UK based site, has a tremendous amount of insight to offer regarding the LP12 (as well as the pros and cons of the pre/post Cirkus sound).