I think, like Rhetoric mentioned, the dealer sourced windshields typically have both Lexus/Toyota branding and the glass manufacturer.
Even within the 2004 year (and ignoring the Night Vision windshields), the LX 470 and Land Cruiser windows have different part numbers. That's not too surprising, but what is interesting is that autoparts.toyota.com carries BOTH the LX 470 and Land Cruiser parts:
2004 LX 470 Part Number:
Genuine Toyota windshield glass for clear visibility, precise fit, and compatibility with glass-mounted vehicle systems.
autoparts.toyota.com
2004 Land Cruiser Part Number
Genuine Toyota windshield glass for clear visibility, precise fit, and compatibility with glass-mounted vehicle systems.
autoparts.toyota.com
I'm not sure what difference there is, if any. Lexus one is ~$30 more expensive though. The only difference I can find is the part outlined in red is only present on the diagram for the Lexus version. I'm guessing that's related to the rain sensor.
View attachment 4088228
I went ahead and got the Lexus part from Toyota for $435. Great deal compared to 'normal' dealership prices, but still pretty expensive for what it is. No idea when it will arrive, but I'm expecting AGC at this point.