Looks good! For what it's worth my daily commuter / utility bike went for some years having only a steel rod rear-rack (complete with that useless mouse-trap thing) and a plastic crate of some sort zip-tied to hell and back on it. Not sure what kind of crate it was - as memory serves it was like a hybrid between a proper milk crate and those things you see 2L soda bottles on. Yours will work much better, I suspect - if you want to replace those zip ties, something like cable or hose clamps might work, since you've bulked up the rack with those grommets.