Rare Herman Miller Eames Zealand Chair Can u identify it?  

I have a Herman Miller designed by Charles Eames Zealand typical grey moulded LAR RAR,Zenith type chair. But...it has a desk chair base that rocks, swivels, and has castors. It has all the correct stickers and a black date stamp of what I believe is 1960. It also has the sticker of the retailer, Business Sales Co. Inc. It is almost perfect and the base seems to be all original. I can not find another example. Is it that rare? Can anyone help with further ID or any other information? I find the secretary model but none with arms. Thank you for your kind attention. I am perplexed.
(edited by DA - no phone numbers please)