Here at Ebay Spain, a guy has been selling a complete Jap Pulstar AES, at first without telling it was a conversion.
I think someone contacted him, because he added (in smaller/not bold letters than the rest of item description) that it was a conversion.
That conversion came from Atomikwave too: I was looking at a bid from him for one Pulstar conversion; somebody bought it; one-two weeks later that guy was sellng that Pulstar... coincidence? I think not.
Anyway, I think I have at home some picture which marks where to press an AES cart to open it: it was useful to me; I'll post here if I find it.
But the risk is there: you can damage the sticker (from light marks/crease/wrinkle to slashing it in two)...
Too, there are legit carts aroung there which can have: reprinted insert, and/or reprinted cart sticker, and/or even reprinted manual.
Imagine someone own a expensive game with the insert sunfaded.
If someone can provide to that someone with a high quality reprinted insert, then if he plans to sell the game and do not say the insert is a reprinted one... more buyers will be interested in purchasing the game, price will be higher, and if someone finally opens the cart, he will find a legit cart...
EDIT: Here is the picture (I found it in the internet a time ago, but I can't remember now where):