I had a similar service comment about pump seal and crank only but when I called the Lexus dealer to inquire about the timing belt he confirmed it was replaced by matching the service record to the actual invoice and bill which showed the timing belt was replaced. Therefore in my case it was replaced with the same comments that you are getting. Call the Lexus dealer and if you get a good one like I had he can look it up!

 

You can also sign up on the Lexus site. Once signed in, you simply add the VIN to your stable. Once in, you can see all Lexus dealer service history records. Here was mine:

 

Yep. That kit is sold online at many places.

Make sure to get the gray Permatex Gasket Maker for the stat. I also put a little over the outer-side edge of the gasket rubber on the block side. My last change I noticed iron pitting and it looked like it was about to leak past the gasket (that was many many miles ago and thus far no leaks). I will do the work and then let it sit overnight for Permatex to set up before filling coolant and starting.

Always dbl/trpl check belt alignment before closing things up! For me, to avoid any confusion of belt marks and metal marks (oem alignment stuff), and to guard against any movement in crank or cams, I put witness marks (sharpie) on belt to gears, then I match up the new and old belt and transfer the marks to new belt. Makes it easier putting new back on, then just verify the oem marks make sense. Done it this way 3x already.