I bet they have no clue how it left so they can't say it was stolen. Apple has ditched quite a bit of their historic equipment over the years probably in many different ways.
Anyway in CA:
If the theft offense is a misdemeanor offense, they have 1 year to charge you.
If the theft offense is a felony, they have 4 years to charge you.
Difference between misdemeanor and felony is the value of what was stolen.
BUT:
Receiving Stolen Property and the Statute of Limitations for Theft
Since the crime makes it illegal to possess stolen property, as long as you have the stolen property in your possession, you are still committing the crime.
So they can charge you with that forever as long as you have the stolen item.
What I collect: 68K/Early PPC Mac, DOS/Win 3.1 era machines, Amiga/ST, C64/128
Nubus/ISA/VLB/MCA/EISA cards of all types
Boxed apps and games for the above systems
Analog video capture cards/software and complete systems
Bookmarks