United Services Manuf. Co. Ltd.
Matthew Zubrot has informed me that card no. 18 has Mills as a Chelsea player on the front of the card, but he's listed as a Leicester City player on the back. Welsh international Tommy Mills was a Leicester City player. George Mills was at Chelsea and he is the player shown on the front of the card. I've included a card from the R. & J. Hill series of Popular Footballers.
I am not aware of an amended card being issued.
18. T. Mills (Chelsea (front) - Leicester City (back))