Probably the reason there is so little stuff on non-Federation ships is that Trek, for the most part, is "canon" based, therefore, the amount of time and money that would be required by Paramount to produce detailed deck plans and other information such as power systems, crew compliments, weapons...etc, etc for those vessels would be prohibitive simply fom a cost perspective.
However, there could be a 'canon' solution.
Paramount could set up a contest for fans to design the interiors/deck plans for the most popular non-F ships and choose the one, on its overall merits, they feel should become the 'canon' version.
Perhaps all the Trek forums could participate and through a process of internal selection, send their contributions to a central point for further peer review. That point could then collate and manage all the submissions and through a process of critical review (I am sure there are thousands of Trek fans that would love to participate in that) a shortlist of 50 could be put through to a panel of respected online, non-professional Trek ship designers/engineers. They would then whittle the submissions down to final 5 for Paramount to choose from.
A reasonable and approppriate prize would be offered and the contest would take place annually.
This idea is just off the top of my head as I write, but it might be a way for the fans to contribute positively to Trek and for Paramount to reward Trek fans for their loyalty - and their cash.
Any thoughts?
However, there could be a 'canon' solution.
Paramount could set up a contest for fans to design the interiors/deck plans for the most popular non-F ships and choose the one, on its overall merits, they feel should become the 'canon' version.
Perhaps all the Trek forums could participate and through a process of internal selection, send their contributions to a central point for further peer review. That point could then collate and manage all the submissions and through a process of critical review (I am sure there are thousands of Trek fans that would love to participate in that) a shortlist of 50 could be put through to a panel of respected online, non-professional Trek ship designers/engineers. They would then whittle the submissions down to final 5 for Paramount to choose from.
A reasonable and approppriate prize would be offered and the contest would take place annually.
This idea is just off the top of my head as I write, but it might be a way for the fans to contribute positively to Trek and for Paramount to reward Trek fans for their loyalty - and their cash.

Any thoughts?
