new marantz sc7 and sm7 system I bought from Japan in 1979.

Some of what you've listed have been sold recently on ebay.  Keeping your eyes on the site will give a pretty good idea of their current worth.  Of course, what people are asking is not necessarily what the pieces are bringing.  ie: (http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2055119.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=m...)   (http://www.ebay.com/itm/rare-vintage-black-marantz-sm7-esotec-power-amplifier-152-watts-per-channel-...)    

Thanks for you opinion but I just want to know whats it's worth.  I don't plan to sell any of those items.  I would always keep my possessions no matter what.  I plan on taking them out of the boxes soon and get a cabinet that will hold all of the items because they are very heavy and I have many pieces of stereo equipment.

So why don't you list them on the marketplace site instead of trying to back hand sell on the forum? And without having this stuff serviced, I say it's all worth the current price of scrap metal...

You,  "...have used them with US and European voltages." and they're still, "brand new"?   Neat trick!  

I bought these from Tokyo's Akihabara Electric Town.  These were built for US market and are have adjustable voltages for multiple countries (110v to 240 volts).  They have the US electrical cords.  I have used them with US and European voltages. These are the Gold Anodized versions.  They are awesome when the system is setup.  I bought a set of the big Pioneer speakers from Japan also along with the Top of the line Pioneer PL1000 turntable that has also been boxed since 1982.  I have many other vintage stereo electronics that I purchased from Japan that are also in mint condition.  Dynamic Range expanders, equalizers, Teac tape decks, akia reel-to-reel tape decks, All are with original papers, manuals, and boxes.

To add to what Rodman said, what voltage are they?  If not US, they will need a step/up transformer.

Constructed with an untold number of electrolytic capacitors, that are now over 37 years old, it would be a good idea to be certain the pieces are actually functional, before trying to sell them. What you get will depend on the yen a buyer might have for old SS Marantz gear.