Fortunately, the Panasonic contactors used in the Better Place pack can be found from time to time on eBay, and I picked up a couple from a Canadian seller at a very reasonable price. I like the packaging on the Better Place contactor/precharge module and since I designed the mount for it in the first place, it went back on pretty easily.
I took the opportunity to ground the shielding on the inverter cables and revise the wiring to the time-delay control relay. This setup certainly looks cleaner than the former one, and all of the terminals and connections are safely contained inside the plastic housing.
We'll test this in the neighborhood for a bit before we go too far afield, but I'm hopeful that this will solve the precharge challenges. There is lots more I want to do, but this needs to be stable and reliable before moving on.