You can now trade Lucky Stamps with your clan mates!

When you go to your stamp album, any non-diamond collection, you will see a button next to the stamp set name where you can ask your clan mates for a stamp you're missing.

Press that button and select the stamp you want to request and if your clan mates have it available you will receive it your clan perks.
You can request 1 stamp from your clan mates every 24-hours.

At the moment, Diamond and Gold stamps can not be requested.
If there are no eligible stamps to request (i.e no regular stamps) then the request button will not appear.