Recycle E12 sockets from a string of outdoor patio lights for Christmas decorations
If I follow your hoping to salvage the sockets out of this string and use them for a custom made string of lights.  Since these sockets go for about $2 or so, you'll save something like $100.  

I think it's a good idea as long as you make this a low voltage string of lights.  I don't think 120V homebrew stuff is a great idea for a lot of reasons.  

But say 12V - that's not nearly as dangerous, and power supplies are inexpensive and easy to find.  With LED lights, the load is much smaller than with incandescent, and these types of projects are easier to pull off since voltage drop doesn't amount to much with a reasonably big wire.  Low voltage LEDs should be less expensive and last longer because they don't need as complex a circuit in each bulb - a simple regulator instead of a full blown power supply circuit. The main conversion gets done in a wall wart that can be easily swapped if it breaks. 

If you cut off those sockets with a bit of lead, you could connect them to a two-wire backbone cable and let them hang. I'd use a 14 gauge or 12 gauge twisted pair bell type wire rather than a cable with a jacket like an extension cable.   That shouldn't be too hard to find.