Matching pair based on cosmetic condition and the lack of any wear on the bearing I would think they're only a couple of years old.
Genuine Cirkus Sub Chassis
Excellent bright condition. Bearing has mirror finish.
Cirkus Bearing Product History
1993 Cirkus bearing introduced (LP12 S/N 90582)
Cirkus Bearing Product Description
The Cirkus upgrade to the LP12 focuses on bearing performance and the connection of the bearing housing to the sub-chassis. The improved bearing and stronger sub-chassis arrangement provides the turntable with greater stability and ensures the bearing sits perfectly true to the chassis of the turntable. This in turn minimises the risk of turntable platter movement with respect to the sub-chassis and arm. Even the slightest movement will introduce audible degradation to the reproduced signal. Together the changes to the bearing and the sub-chassis make an enormous difference to the overall performance of the turntable. The specific changes are as follows:
- The thickness of the bearing housing mounting flange has been substantially increased and undercuts eliminated to make it many times more rigid. This also allows the use of larger mounting bolts.
- Increased distance between top and bottom liners in the bearing housing to make it as stable as possible eliminating even the smallest amount of rocking.
- An increase in the height of the bearing housing from the top of its inner liner to increase oil capacity, ensuring proper lubrication of the top bearing at all times.
- Double thickness sub-chassis to improve rigidity, reducing flexing and improving control of the relationship between key components
Cirkus Bearing Specification
Fixed using three M4 by 10 Socket hex head cap nickel plated screws.
Requires a bonded Cirkus, Kore or Keel sub chassis.
Source Lin Docs 1996