Same problem with the keys I got cut at Ace hardware. Cannot lock/unlock the fork. Do you recall if the keys from the ebay vendor had any stamped markings?I recently had two made at my local hardware store and they work if the fork is unlocked but are not long enough to release the fork lock. I ended up having two made with an eBay vendor but I had the key number.
I also have contacted a locksmith near me who has helped me handling the stuff,I had lost a bike code last week. there was no other option to get the key code. but I hired a locksmith fort lauderdale to handle this stuff. They created a spare key code without removing the key cylinder.