In regards to George V's wedding ring. He did wear one.
As can be seen in Pope-Hennessy, page 266; Queen Mary wrote to George on the morning of their wedding stating:
"I should much like to give you a wedding ring if you will wear it for my sake - I therefore send you herewith one or two to try on for size - Let me know the one you choose at once & I will give it to you in the Chapel."
Furthermore, Field writes on page 97 ,"Prince Albert, King Edward VII and King George V all wore wedding rings on the fourth finger of their left hand, but since 1923 a tradition has been established by the male members of the royal family of wearing a narrow wedding band next to the crested gold signet ring on the little finger of their left hand."