To add my ten pennies worth. When quiet, or need to do other operational tasks (obtaining airways clearence etc.), I quite often clear an aircraft to land or touch and go prior to the final call.
I do not require a final call to be made after this time, and do not expect one. Otherwise i would wait every time for the final call before issueing the clearence.
You are not in the wrong, and if you feel comfortable doing this then carry on. But from my point of view, the final call is not required if you have been issued the clearence.
The controller would have sterilised the runway as soon as he/she has cleared you.
Safe flying.
