I will never again buy on GB. Bad experience. Bought a TC Hawken advertised in good condition. After 11 shots the hammer would not catch in full cock. Removed cap lock and found the tumbler worn past the notch. I asked the seller to contribute to the cost of replacement parts. He refused. Filed a claim with GB. They refused bc I removed the lock.
Burned once. Never again.
GB is a tricky thing. I've bought Muzzle Loaders that were shot and never cleaned but looked nice on the outside. Some with defects not listed, and one that was
STILL LOADED! The last one was a 50 cal CVA Hawken Flintlock which I bought from a first-time seller (a mistake) It had a 1" barrel instead of the 15/16" I was wanting. I forgot CVA made them in both sizes. The rear sight had been painted black which flowed onto the barrel (didn't notice it in the photos). I swapped it out with a fixed one and was able to get the paint off the barrel without killing the bluing.
For me, to increase the chances of a successful buying experience, I ask a lot of questions. I ask for extra photos. I buy from experienced sellers. I've bucked that on a few rare items I've really wanted (like the FL Hawken) and ended up with something different than what I expected.
In your case, that was on the seller's part and they should have made it good. I will not list something that is defective or unsafe. I completely clean it before I take any photos. There's nothing like a coat of dust or crud to turn a buyer off. I provide 4 or 5 pictures of each side; right, left, top & bottom plus muzzle and butt. I give a detailed description, especially pointing out any flaws or defects. I don't like "gotchas" and neither do most folks out there. They also have a 3-day right to inspect, although most folks won't pay the money to ship it back.
After a purchase. the first thing I do is take the gun apart,
inspect, clean, and lube it. Their policy of saying they won't help you is total BS! I'd like to see where it says that disassembly is not part of that process.
You can find things there that you haven't seen in a while, often from someone getting out of it or another selling off an estate. Lastly, look at the seller's rating. If they're new or have far less than 100% good Feedback, pass on by! Also, beware of Gun Stores and Pawn Shops. Chances are all they did was snap photos and list them. I'd rather buy from a Muzzle Loader person. Lastly, set a limit you are willing to pay for the item including shipping. Although, I have lost auctions by as little as $1!
Sorry for your troubles,
Walt