Btw Catlabs says the following about the revisions. But none of their numbers match this unit.
BULLETIN # B019
Rotation Motor Upgrades for the CPP-2 and the CPA-2 Processors
Introduction
Newer systems, like the 3000 series EXPERT Drums, require increased strength in the rotation motor circuit. This extra load can make the rotation speed of the tank or drum sluggish. The 3000 series EXPERT Drums create the heaviest possible load for the rotation motor circuit.
Beginning production of the CPP and CPA had a single-bearing rotation motor.
CPP Serial # ARXXXX-10593
CPA Serial # ARXXXX-10312
1st Upgrade: The single-bearing rotation motor was replaced by a double-bearing rotation motor.
CPP Serial # 10594-20455
CPA Serial # 10313-13309
2nd Upgrade: The rotation motor circuit was strengthened to accommodate larger loads, that is, 3000 series EXPERT Drums.
CPP Serial # 20456-21999
CPA Serial # 13310-21999
3rd Upgrade: A stronger rotation motor (the same as in the ATLs) was introduced and the rotation-motor circuit was strengthened to accommodate the new motor.
CPP Serial # 22000-present
CPA Serial # 22000-present