Garrett turbo rebuilt tag question

[1BUICKT]

A little while back I purchased a used 86/87 turbo for cheap off of the internet. I noticed that it has this rebuild tag on it with what Im assuming are the part number and serial numbers. Is there any way to tell when the rebuild occured by these numbers or is there a reference that any of you know of that I can check? From what I can tell the turbo seems to be in great overall shape.

Thanks,
Johnny

 

[mikes86ttop]

Last year I bought a 30k mi motor and trans out of an 87 GN wrecked in the rear in early-mid 90's, during inspection I found the same tag on my turbo, closer inspection I realized the turbo was practically brand new, not one spot of oil,crud, or exhaust build up any where on the turbo, kinda seemed like the turbo was replaced and the car was wrecked pulling out of the parking lot. Needless to say it runs perfect...Mike