OpenRC Tractor - Motor part 12a - alternative when using standard servo for steering

I mounted a standard servo for steering. I have used one mounting hole in the chassis and double sided tape for fixing the servo. I also had to cut the fastening tabs on one side of the servo and had to sand this side to fit the mounting hole in the bottom of the chassis on the other side of the servo...
Unfortunately, the right "engine part" doesn't fit anymore, because of the servo. So I made a cutout in this part...