Jim,
On mine, which I suspect is the same as yours, the dip stick is on top of the transmission and IS not accessible from the rear or anywhere else. The access panel has to be removed to get at it which on mine, required the removal of closet doors, a board at the bottom of the closet frame, then the "L" shaped access panel can be removed, as the short part of the "L" has to be tilted under the remainder of closet frame.
To say this was designed and/or built by idiots (IMO) is an understatement!
Jeff