The repair shop finally showed up with the correct lamp yesterday. I wish I had thought to take a picture of it. It's definitely a more complex part than the old TY-LA1000. It's surrounded in a metal housing with heat sinks on it, and the lens seemed very thick. It's also complicated to replace. The repair guy spent about an hour and a half on it, taking apart the whole back of the set just to get at it.
It's working fine now (knock on wood), hopefully it will last. The invoice has it listed as $830 (which Panasonic did cover).