Hey! I work at the Kids Planet @ Sheepbridge (or I will when I go back after mat leave), don't feel like you have to wean him off his dummy for nursery, you can send one in with him no problem and they'll store it in a dummy pot with his name on when he's not using it :) hope this helps!
My little boy goes to a kid's planet but the Newbold one and they have never had an issue with him having a dummy and if I forgot it they had spares. Piece of advice though I'd wean him off the dummy sooner rather than later as I wish I had, I managed to wean my little boy off his dummy by 2 years but I felt like he was getting more dependant on it the older he got, also the nursery can support you in loosing the dummy
you can buy personalised dummies so it will have his name on it! Just type it on google & a few websites will come up for them! Im sure if another baby got hold of it, they should surely give it a wash before giving it back to the right child ??? Xx