I've lost the body mounts over the years so I desided I'd build new ones. I didn't have the originals to hand, so the shape of the parts are freely chosen and built with the focus on easy printability.
Parts: 9115049

I added a version where you can change the mounting pin. if it breaks, you can quickly replace it and save printing time and filament.
I added holes to be able to screw the pin if necessary, I didn't need to do that as everything was tight enough
my print settings:
0.2mm
4 perimeter
20% infill
no supports
shellholder_rear_v2_lower: this version has the pins a little further down
Please note: since I had to replace both parts, I don't know if they each fit in combination with the originals, I'll be happy to get feedback!
The author marked this model as their own original creation.