NOVA tube extension

[NOVACarl]

When I first got my NOVA December 1999- the Benelli catalog showed a 2 shell and a 4 shell extension tube. The next year Benelli showed only a 2 tube extension. Are there any 4 tube extensions left out there?

[Drundel]

Check gunbroker.com i used to see them there, but man it ain't gonna be cheap.