The entire injector is no longer in production. You can, or at least a few years ago, still get nozzles, springs, and shims. If the nozzle is all you need, any denso pump rebuild house can get the parts cheaper than getting them through Yota, and I'm pretty sure the part number is etched on the side. If you need the whole thing, you might be in for a search.
The "Holder and nozzle set" part number if 23600-58020 which does not show as a good number at 1st Toy.
As mentioned, on the side of the injector/nozzle set are the denso part numbers that "any" denso shop can read and that's what they would use to get the parts needed. I would imagine the same Denso shop would be your best source to ask about replacement bodies as well.