Marble race blocks (Hawthorne Hills in NE Seattle)

Small set of blocks for constructing a marble race (pictured). A few blocks are stained from spillage from a 9-year-old's crystal growing experiment, and all need some cleaning. You supply the marbles. Please read instructions, below.

Give me a 4-hour window in which you will actually come for them if chosen. This time window should start no earlier than 12 hours after you email to express interest, but does not have to be as early as 12 hours after you email! I would rather have an accurate time estimate a bit farther in the future than a time that really doesn't work for you so that you end up backing out. I check my email typically 2-3 times a day, so you can expect some delay before I respond to your request. I can leave the set outside for pickup if I will not be home when you want to come, but I get enough lead time to do this.
No-shows go to the bottom of my list in the future.