Love the check book idea - either as a gift to someone in recovery or yourself like you said as a frequent reminder. 29 years - congratulations - the ritual sounds amazing.
I buried my one year chip with some mums I planted at my parents headstone. I wasn't sober when they passed away so that was important to me.
I visited Bill Wilson's gravesite a couple of years ago - a glass jar was at his headstone with all kinds of colored chips, personalized chips and 20 and 30-year medallions that people had left.
A sign at the jar encouraged people to take one but to replace it with one of your own as an exchange for the next person. Very cool.