Eames Aluminium Group EA-124 - help / info needed  

Love this forum because of all the knowledge people contribute, could use a little help
I need some help identifying the age (era) of my aluminum group lounge chairs.
I have three of them in varying conditions, recently downsized so I would like to sell two of them and want to make sure I'm providing the correct information and I am asking / getting a fair price.
1. the lounge chairs have the forged aluminum bracket that attaches to the chair side rails and 4 star base. It is the tilt and twirl option also not the rigid. It is NOT the black metal bracket seen on newer models. Stamped in the aluminum is the Herman Miller name / Logo and pat no. 3041109, 3024068
2. the chairs do not have the bracket at the front edge of the chair where your legs rest, I have seen images of chairs that have a bracket at both the back of the chair (shoulder area) and at the front edge (back of thigh area) mine just has the bracket across the back. was wondering if that was a sign of production era.
3. One of the chairs has the full tag still on the chair, another has about 2/3rds of the tag and the other is missing the tag, it starts off by saying - "this article is made in compliance with an act of: Dist. of Col. Approved July 3, 1926, Kansas approved April 24, 1929, New Jersey....etc." Also says on the tag "Certification is made that the materials and metal if any in this article are described in accordance with state law." does this help with value?
4. the chairs are all aluminum: 4 star base, bracket explained above, side rails and side arms, the seat material is the black fused ribbed vinyl. All of the chairs have head rest cushion too, black hop sack material - all of them remarkably are in great condition
Any information on the history / value of the chairs would be greatly appreciated, I am Guesstimating it was made between 58'-68'. any help with market value or best place to sell them would be helpful too (is RADAR and option for USA)

I have some restoring questions to but this is already to long I'll ask those later.
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