Latitude E5550/5550 bottom case part number

Hello from Germany!

I bought a E5550/5550 with a locked BIOS and a bad keyboard a couple of days ago.
After resetting the BIOS pw, install a new keyboard and a SSD the machine works fine with W11 pro.
The bottom case has a "plasic issue" on the right front corner.
How can I figure out the part number of the bottom case w/o tear down the complete machine?
My E5550/5550 is with the INTEL Graphics onboard only. No discrete graphic adapter is installed.
Seems like at least two different cases for this machine:

- 01TRJX Bottom Chassis Case -33A
- 0TC84N Bottom Chassis Case -00A

any hints for me in this case?

Thx and best regards

Peter