I would remove the comma after afternoon. Not sure why, but if you recast the first phrase "A book arrived in the mail yesterday afternoon: . . . ." you would not have a comma; that makes me believe it would not have a comma in its original form.

I would certainly have typed it automatically without the comma.

Peggy pointed out to me when we were talking about it that she would not put a comma after Jr.'s. I admit I missed that, but after considering the matter I agree with her. The comma does nothing for the sentence.

I would leave the 's where it is. That is exactly how you would say the phrase if you were reading the sentence aloud. And you should not sow too many commas into a sentence lest you become known as a comma suturer. Sentence erections are funny things.


TEd