Thanks for the advice... I had figured there must be a way to simply "unrequest" them online like there are for other MSP's. It was a simple issue: They were two quick, low-paying shops on a route I was doing - (over an hour from home and requiring an expensive ferry ride). I literally drove by one of them three times during my other shops today and could see it from the parking lots of two of the shops that I did. It would have been a nice little pickup.
However, as the shops were still unassigned (to me, or anybody else) and I don't have self-assign abilities with Maritz yet, I really, really did not want to land them after leaving the area. My opportunity to do them had passed. (Alas.)
I ended up calling Maritz and leaving a voice message requesting that they not assign me.
Hard work builds character and homework is good for your soul.