from django.db import models

class MyModelBase(models.Model):
  class Meta:
    abstract = True
    
  field1 = models.CharField(max_length=256)
  field2 = models.BooleanField(db_index=True, default=True)
  #....
  
class MyModel(MyModelBase):
  @staticmethod
  def create_from_archived(object):
    return MyModel.objects.create(id=object.my_model_id, **dict([
      (fild.name, getattr(object, fild.name))
        for fild in object._meta.fields
          if fild.name not in ['id', 'my_model_id']
    ]))

class ArchivedMyModel(MyModelBase):
  my_model_id = models.IntegerField(db_index=True)

  @staticmethod
  def create_from_instance(object):
    return ArchivedMyModel.objects.create(my_model_id = object.id, **dict([
      (fild.name, getattr(object, fild.name))
        for fild in object._meta.fields
          if fild.name != 'id'
    ]))