Hi Joe and thank you very much for your reply. I think a last login would be useful.

I think my colleagues issue is that he has been used to managing the society's old website on his own, he has apparently suffered a number of brute force attempts to login to the admin on the old site ( which was an over the top complicated Wordpress affair that he didn't really "get" ) and he just wanted to be sure that the evoice site was secure. The last login might do just that! 

He was used to being notified when another admin logged in to the old site and just expected that to continue I guess.

Many Thanks

Dave