Can anyone decipher an Acer model number suffix?

I bought two Acer 7735Z laptops from 2 different stores last week. They both are advertised as model 7735Z, and both claim the same specs, but their actual models numbers are slightly different. The one from Wal-Mart is Acer model 7735Z-4000, and the one from Staples is Acer model 7735Z-4613. E-mailing Acer did not help, as they just said the specs are the same for both, but would not say what the differences were.

Does anyone know how to decipher the suffix on the Acer model number, or if indeed there is a difference between them?

Thanks in advance.

 

Here's an FYI update after running "Everest" (a suggestion from another forum):

It appears as though both model numbers are identical in hardware as far as Everest can tell. The only differences between the Everest reports on the hardware (besides H/W serial or ID #s) were that it found a driver called "Wdf01000" on the 7735-4613 laptop that was not on the other, but this appears to be benign as far as I can tell from searching the web.
Some of the lines in the "DEBUG" section of Everest were different between the two laptops, but unless someone tells me different, I am assuming these differences are unimportant (unintelligible to me anyways).

So unless Acer made a subtle difference such as change the webcam (Everest just identified it as a "USB video device"), my guess is that the two model numbers have identical hardware and the only reason for the different model numbers is so you can not get one store to price match another (an anti-competition thing).
Therefore unless someone knows of a better program than Everest, or has further info based on this post, they appear to be identical.