670 / 671

The Eames lounge chair (670) and ottoman (671) is probably the most iconic Eames design. When someone says "Eames chair", they usually mean this one. It's actually one of my least favoriteHowever, this early example Farnsworth just listed for sale got me excited.It has a number of features that don't show up very often. It's also pretty much as early as it gets.
Source: Farnsworth

First, there's two snaps, instead of the normal clips.
Eames Office employee Parke Meeke remembers "the first 50 or so sold were basically put together by hand." Then, with the success of the chair, Charles and Ray made adjustments, which included changes to the way the cushions clipped on. (An Eames Primer, by Eames Demetrios)  The use of snaps to hold the cushions on is something I don't think I've seen before. 
The early snaps are on top and the later clips are on the bottom.

I've also never seen a handwritten contents label: 50% down and 50% feather fill.
The address is the Eames Office, 901 W. Washington Blvd., in Venice. 

The 671 also has slip on glides, which is rare, but they do show up now and then. The more exciting aspect of this one is-- it spins. 
A swivel ottoman rarely comes along and surely denotes one of the earliest examples. 

Exploded view drawing by Eames Office employee Charles Kratka, with lettering by Sister Corita Kent!

The ottoman base is described as "Cast aluminum with machined pivot shaft cast in. Revolves in two oilite bearings."

This early Herman Miller ad, designed by Deborah Sussman, shows the slip on glide and mentions the swivel ottoman.
The "..warm receptive look of a well-used first baseman's mitt” is a quote from Charles. 

Lounge Chair, film by the Eames Office, 1956
The film was made just as production started. Skip to 1:00 to see the spinning ottoman.

The swivel base of the 671 was also used for the Eames-designed Stephens Tru-Sonic loudspeaker, also from 1956.

In this this 1956 Herman Miller brochure announcing the 670-671, there's no mention of the swivel ottoman. I'm assuming this means it didn't last long at all--perhaps weeks or months. The story goes that the spinning ottoman was bumping the chair, so they decided to go with a fixed base soon after production began in 1956. A rotating ottoman also seems totally unnecessary. So, if you have one, you can send it my way.

It doesn't seem like too many people took the Naugahyde or fabric options that were offered.

When I was at the Eames House several years back, I asked about the worn leather on the lounge chair in the living room.  The explanation given to me was that they used glove leather on the very first chairs produced. I guess they were going for that "mitt" look. The material proved to be too soft so a sturdier leather was used. Recently, after the contents of the Eames house living room were moved to LACMA for the California Design, 1930-1965: "Living in a Modern Way" exhibition, I noticed the lounge chair didn't make it into the recreation of the living room in the exhibit. I asked about it and was told it was too fragile to move. Once the exhibition was over and the contents were moved back to the Eames House, (after some extensive restoration was done) I noticed a new chair was in the living room. I wonder where it's at? 
Image: Handcrafted Modern, by Leslie Williamson