My Epilog is old enough that it came with a Coherent-Deos laser tube - a big relief!
I had to have it re-gassed back in May after 12 years service.
The guy who did the re-gassing said that he won't touch Epilog's own tubes as there is always something else wrong with them - so that a simple cheap re-gas turns into a really difficult and expensive exercise. His theory is that Epilog got the licence to manufacture an old and not-very-good tube design.