The partition panels (MB part name) are attached using #12 flange head hex screws and #12 fender washers (both available at bolt and screw stores). You might also try a MB dealership (part number N007976 005202). They might have them in the correct (I think) CAD plating.
The seal is installed as shown in my sketch (glued to the partition panel first).
I had to use an awl to align one partition panel hole with the matching body hole, against the compression force of the seal, in order to start a screw in an adjacent hole. Not an easy undertaking.
Here's the sketch. View is from the top looking down at a cross-section of the panel and the body.
Good Luck
Tom Kizer