As far as I know there's no way to put something back after you've dragged it into the fireplace. Maybe if you exit the game and load it again it'll appear back but I doubt it.
You might be able to get a new coupon using the localization file though. If you write the script to get the letter in which the hug coupon is given (getletter C3_MissNancy_hugCoupon) you should get a new one. Not that I've tested it, but I mean in theory it should work.
As far as I know there's no way to put something back after you've dragged it into the fireplace. Maybe if you exit the game and load it again it'll appear back but I doubt it.
You might be able to get a new coupon using the localization file though. If you write the script to get the letter in which the hug coupon is given (
getletter C3_MissNancy_hugCoupon
) you should get a new one. Not that I've tested it, but I mean in theory it should work.