Moving multiple attributes to a new table - please help!

The very words 'copy attributes' should send shivers down your spine
as a Rails developer. It really sounds like what you've got is a
third object that is related to packages and receipts -- user/person/
addressee or something of that sort. I'd think something like:

class User < ActiveRecord::Base
  has_many :packages
  has_many :receipts
  ...
end
(the class above carries the data you want to copy -- name fields,
etc)

class AddPackage < ActiveRecord::Base
  belongs_to :user
  ..
end

class Receipt < ActiveRecord::Base
  belongs_to :user
  ...
end

Your User class could have a method that "transfers" the item from
"Inventory" (I don't see any class relationship for that) to Receipts:

def signed_for(add_package)
  self.receipts.create(:add_package_id =>
add_package.id, :picked_up_at => Time.now)
  # some code to remove add_package from inventory
end

Note: It's MUCH better to put this type of business logic in the model
and not the controller.

HTH,
Andy