Matt,
Your last photo holds the key to those two little "extra" parts. Your wiper motor shown in the second photo is a very late '32 or maybe not '32, but rather '33 or post-'32 service part with a snap-on cover on the back. Only in this case someone has adapted the '32 back cover with those two little pieces normally attached to the wiper motor casting (not loose as in your case) with two round head slotted machine screws to give the wiper motor the appearance of a '32 wiper motor. Please consult page 16-12 of your copy of the book.
There's nothing missing from the wiper motor in your second photo except the deeper original snap-cover with dimples on the sides and no holes for screws.