I got it originally from the old mod portal, which is currently up, by the way. I can't find it on there now, but I see a couple of other UFO variant mods, some of which likely used some of your UFO variants. I don't have an unmodified version, however the one I have is probably better because all I did to change it was remove some of the redundant craft data which didn't need to be there. People have said Darkened UFOs are better but yours don't seem to have any flaws from what I've seen and I like the designs better because it only changes the inside. I'll add the disclaimer that I may have made other changes which could cause problems--I was working on incorporating it into my upcoming mod but I can't remember how much I've done to it. I think the changes are minimal or none. I added the version I have below.
I'm (very slowly) working on some battleship variants. I did some rotations for the middle floor and then made the top floor way more interesting in each variation. If you're interested, maybe I can hurry up and finish them so you can add to your mod, if you plan on updating it at all.
I can do routes sometimes. It usually bores me also, but I came to understand how it works at some point, so I am now competent at the task and every once in a while I enjoy it. What I would need to know is what sort of general design goals you have for it. I mean I can place random enemies all over it, or I can design it with some purpose in mind. Just a general explanation is good, you should probably just post it on some thread asking for help and I may or may not ever get around to doing that.