More aggressing code reuse

ram/roster/admin.py

@@ -161,15 +161,7 @@ class RollingStockAdmin(SortableAdminBase, admin.ModelAdmin):
     def get_queryset(self, request):
         """Optimize queryset with select_related and prefetch_related."""
         qs = super().get_queryset(request)
-        return qs.select_related(
-            'rolling_class',
-            'rolling_class__company',
-            'rolling_class__type',
-            'manufacturer',
-            'scale',
-            'decoder',
-            'shop',
-        ).prefetch_related('tags', 'image')
+        return qs.with_related()
 
     @admin.display(description="Country")
     def country_flag(self, obj):

ram/roster/models.py

@@ -11,7 +11,7 @@ from tinymce import models as tinymce
 
 from ram.models import BaseModel, Image, PropertyInstance
 from ram.utils import DeduplicatedStorage, slugify
-from ram.managers import PublicManager, RollingStockManager
+from ram.managers import RollingStockManager
 from metadata.models import (
     Scale,
     Manufacturer,
@@ -120,6 +120,8 @@ class RollingStock(BaseModel):
         Tag, related_name="rolling_stock", blank=True
     )
 
+    objects = RollingStockManager()
+
     class Meta:
         ordering = ["rolling_class", "road_number_int"]
         verbose_name_plural = "Rolling stock"