Little bit, they are are nice bikes, but don't worry about being too precious with it, they are pretty tough. (And relatively common, albeit not necessararly in this condition. If you want to treasure it, it would be worth tracking down the equally good condition parts that would of been original to it. I don't see much point in treasuring it as being original condition if it isn't original spec.
From what i can gather the only original spec bits thats different are the break levers/sifters ,and as the LX ones on it are like new should i really bother ? could i find XT ones in as good condition as those LX ones ?
I have always had Marins when i was younger ,so finding one from back in my hay day,as mint as this ,In a large sized frame for my large sized frame,probably means more to me than most people care to understand
"Sell crazy some place else...we are all stocked up here !"