Hello all you Altec-Lovers

My Name is Michael from Germany and i´ve got a question about a 604 8L horn - cabinet which is constructed from the customer Musicconnection.
They built a speaker, using the actually design of the Duplex 604. They call the speaker Dynavox Imperial.
Here is the link :
http://www.musicconnection.de/imperial.html

Now my question :
Does anybody know something about this cabinet?
If not, what cabinet could i use best for the 604 8L?
Perhaps also as horn-construction.

Any help is really welcome!!!!

Thanks and always have a nice day,
Michael

PS : Sorry for my bad english.....