Up for sale here is this set of 4 used 7189 vacuum tubes. These are all labeled IEC Service Master Gt Britain, so I believe they are Mullards.  These are identical, though some have less lettering than the others.  They are all in good working condition.  I tested them on my B&K 747B tube tester, and they all pegged the meter at 120, with no shorts or grid emission, on a scale of 0-120, where 65 is minimum good.  These tubes are guaranteed to work well for you.  Please see my pictures for details.

US shipping and handling is $8, and international is $12.  I accept Paypal.  If you have any questions, please ask.

I have a number of other tubes & sockets, collectibles, Magic cards, and vintage electronics listed--feel free to take a look!