Are you sure that what you got is the real thing? I ordered from two different companies which advertised their seals as Metro-Moulded. Neither was so I sent them back and notified Metro of the counterfeiters.
I spent months swapping emails and phone calls with Metro after they stopped production. They eventually began to manufacture them but they were not even close to correct. At that point they told me they had no plans to reintroduce them.
I hope they have. The Metro sales rep told me their seals would have a trademark or number molded into the block and will always ship in their packaging.