lake cty CA cabs

[ufcgracie]

I am a wine novice who "inherited" a couple of magnums of Lake County , CA cabernets. I am hoping to determine if they are ready to drink ( or are they past their prime?) and whether they are decent wines or just swill.
The wines are:
Kendall-Jackson "the proprieters reserve" 1986 magnum Cabernet Sauvignon

Stuemer 1982 magnum Cabernet

If anyone woud be so kind as to advise this novice whether I should serve either of these to my boss, or with my in-laws I would be in their debt.

thank you