Please help identify these ink stamps on fiberglass armchair  

Any thoughts would be much appreciated, thank you.

If you are in the USA, you almost surely have a chair made by Herman Miller designed by Charles and Ray Eames. The brown bit of paper on the bottom was once a sticker listing the patents. There should be a raised logo (looks like a stylized M) molded into the bottom of the shell, up toward the front lip, with the words Herman Miller beneath it.
Is it upholstered? That can sometimes help with a date.
The upper rubber stamp, which is hard to read, may be a manufacture date, but I can't make it out.  The round rubber stamp is most likely from a distributor or maybe of the contractors that made chairs for HM. Most of those companies included their own embossed logos in the fiberglass as well, and they're enumerated here:  http://www.designaddict.com/forum/General-discussion/Where-were-herman-m...
If you arein Europe, and there's no Herman Miller logo, this may have been made by Vitra, which had (and has) an overseas license. Not sure how those are marked; I'm in the US and haven't seen one. 

Thanks Toomanychairs.  I appreciate the information.  These chairs are not upholstered.  The upper stamp is i believe is a date stamp reading 91357 with additional charactors on either side that I can't seem identify.  I have yet been able to see a raised logo however it is possible that I missed it.  Thank you again for the help!!

looks like "Summit Prime" to me. Summit was a fibergass manufacturer for Herman Miller chairs. They used to be caled Zenith.

Thank you bshop22!