Not sure if this will help, but here goes. Create a collection or group(Unlinked collection) with everything in it. I personally would use group, but to each their own. To group select all and press ctrl+G. Then press F9 or goto adjustment box in bottom left hand corner and give the group a name like skateboard. Then when you want to move everything select one object press shift+G->collection. It will come up with a list of collections/groups that the object is a part of. Click the group and then it will select all of them. By using the group you can also select the objects in outliner, right click->unlink. Then to add the skateboard you would just shift+A->collection instance->Skateboard group. It will act as one object. If you need to adjust the objects inside the instance then at top of outliner change mode from View Layers to Scenes. Then expand objects, expand the collection instance right click on the Group name under the instance name and click link to scene. Go back to view layers and you will have a collection with the group name. Make your adjustment(Note this affect all instances) then when done you can select the collection(Group name) right click->Unlink.
