May be you guys know already about that but I thought it may help also to id the bag:
from eBay Guides
"...
Fendi Zippers: If the bag has one, ask about the zipper.
Fendis zipper slides usually have the FF logo underneath, even on the inside zip pockets. (see photos) There are some exceptions to this rule and a few of the
Fendi leather styles have RIRI on the underside.
Spy Bags. Ask for the measurement of the Spy Compartment. Open diameter, from center hinge to hinge is 5 1/8. I have not seen an variation. The replicas Ive looked at ranged from 5 to 5 3/4". Take a look at the hinges and the pin holding them in place. Screws should be placed as shown in the photos in Guide II & III.The ends of the pins in the hinges should feel slightly rounded and smooth to the touch.
When looking at the front of a closed bag, FENDI will be engraved on the bottom of the woven handle upside down and backwards. FENDI will also be engraved on the top front of the woven handle hardware. Directly on the back of the hardware behind the right side up FENDI, engraving should state MADE IN ITALY on three lines, centered, in upper case. Engraving should be clean. A replica may have the MADE IN ITALY engraving, but if you examine the print carefully on a replica, it may look darker in the crevices of the engraving.
The top right side of the woven handle will have two small flathead screws, one larger than the other.
Look for two-tone color hardware, light gold and silver. Its difficult to determine unless youre in the right light.
End Cap of the Braided Handle is Engraved FENDI in gold and placement is at the bottom close to the hinge. The entire end cap is covered with a transparent and raised piece of Glass. It is nicely beveled along the entire edge.
The black hologram tag inside is folded and sewn into the bag. The hologram is heat sealed and will not easily peel off nor will it do so from "sitting in a warehouse." The inside of the fold will be neat and smooth. The print is easily discernable. Ive found the inside of the tags on the replica handbags sloppy. (see photos in Guide II and III) On newer authentic Fendi Spy bags, an alpha numeric code will be on one line on the bottom of the tag. Older Fendi Spy bags may have the A on the top of the numeric code. No need to worry if an authenticity card comes with your bag and the label is not entirely straight. No need to worry about the letters FOG on the card. It is a myth that this denotes a counterfeit bag.
An alpha numeric code that includes the style number will be embossed on a leather strip inside the bag. The style numbers will be on the Authenticity card, but not the other alpha number code...."