Thank you lots! I bought the purse and am now haunting the rehab thread on how to restore the leather a bit before use. The Coach TPF is the basis of my newest hobby, I guess.
I also read the Coach serial number guide of yours, and found it immensely helpful:
http://www.ebay.com/gds/Coach-Serial-Numbers-the-Basic-Facts-/10000000034886433/g.html
Here's a purse that I found while browsing and can spot issues with:
Item: TAN LEATHER CLASSIC COACH STATION BAG 5130 VINTAGE EXCELLENT CONDITION
Listing number: 221442572432
Seller: kdavisjoy
Link: http://www.ebay.com/itm/TAN-LEATHER...130-VINTAGE-EXCELLENT-CONDITION-/221442572432
Comments: The serial number reads H4L-5130, yet it also says that it was made in the U.S. Also, the number indicates that it was made in 1994 (I think I got that right?) but the purse does not look like a 20 year old vintage item, though that could be because it's been restored.
Several plant codes were used at various times for more than one plant. Of those, plant codes G, H, L, and especially M are the most common. None of those should be assumed to be real OR fake, they all need to be authenticated.
Condition of a bag doesn't prove much. Like you mentioned, purses can be restored or just not used much. Just because something is 20 years old doesn't mean it was used regularly for that entire time.
I don't see any problems with that bag.