I can guarantee the contents of the bottles are completely useless for any winemaking application. It’s almost unheard of for a wine, let alone much more-perishable grape juice, to survive in any kind of good condition for that long. What you’ve got are essentially bottles of oxidized, browned and completely undrinkable grape juice. No one would pay for it from that point of view, unless you were perhaps a wine educator looking to teach your students about the ravages of time and oxygen on grape juice.
The boxes, bottles and labels however may well have some resale value for those that like old fruit crate labels, bottles or similar items. As far as value goes, it’s hard to tell. As with any collector’s item (and these wouldn’t be technically called “antiques” by most dealers, being that they are less than 100 years old), the better the condition and the higher the authenticity of the items, i.e. how close are they to their original state, the more you may be able to get for them. Since everything seems to be together and unadulterated, so to speak, this speaks well to this possibility.
Before I get you too excited, however, realize that you probably aren’t dealing with an item a lot of people would be interested in (aside from maybe some WineMaker magazine readers). Your bottles aren’t labels from famous Grand Cru vineyards and aren’t even from any well-known California company. A quick look for “Smil-O” grape juice on the Internet came up blank. Since supply and demand dictate price, I would guess that even though you probably have a scarce item (which would dictate higher price) the demand for your item is probably pretty low. Unless the artwork is spectacular enough to interest an historical collector, you may just want to enjoy your items yourself. I would suggest you do some browsing on collector or auction websites — eBay is the first that comes to mind. You could also try to find antique or collectibles stores that specialize in fruit crate labels or wine ephemera. These buyers are more specialized and, if you decide to try to find a buyer, will probably return a higher price than a general marketplace auction house like eBay.