To all of you, thanks for chipping in and help me with your advices.
This upgraded LP12 seems like a "no-brainer" at this price and, at the end of the day, to represent little to no risk at all.
Upgrades (cirkus and trampoline 2) were installed in 2015 at a local Linn dealer. I guess the table was checked at the same time but, regardless, I will take Varyat advice and have the deck double checked prior to committing.
If everything is fine (wich should be the case), I will offer the 900$ asked and take the plunge.
Your advices were really helpful to me. I'd like to thank everyone who commented.
Sincere regards
Marcandr
Btw, are the SME Series III tonearm and AKG P8ES Supernova VDH2 S cartridge worth keeping for a starter like me ?