Hi, i've got a chance to try a 1979 gibson 335-pro in a few days at a local shop and i'm wondering if any of you guys have had any good experience with it? I've never heard of a "pro" line of the 335 and this 30 old year guitar seems to be in good condition as well. Heres a pick of the guitar i understand it comes with a pro truss rod cover, but this one seems to have one without it? should i be concern with that? how much do you reckon its value is? Cheers.