It is a lovely, old-fashioned sofa, and because it has lost most of its external fabric and stuffing and padding, you can see what's called "eight-way, hand-tied construction":
Each of these coils is individually hand-tied to all its neighbors, at both the top and bottom of each coil. Thus the "eight ways":
This makes a sturdy, stable base for the upholstery, and it lasts for years. The brass tacks and gimp (the fancy braid underneath the tacks) are often found on well-built sofas of yesteryear:
Unfortunately, this sweet thing has seen better days. But oh, how I love the faded-rose color of the velvet, and the little garlands of roses along the sofa's top and trailing down the arms:
This sweetheart is beyond my ability to help it, however, so sadly I left it by the side of the road.
By this morning, it was gone. I want to hope somebody with the skills and/or money saw its potential and swept it up to be restored to its former glory.