Thanks for the kind words on my escort. Unfortunately I have the ADD when it comes to building stuff. I started building that escort like seven years ago and only recently found it waiting to be finished in its little drawer.
Step by step will be impossible as its been too long. In a nut shell, from memory, I cut the top silhouette out of a piece of thick plasticard, maybe .125-.150 of an inch, with a jewelers saw. I then cut the bridge and dorsal bits once again in silhouette from the side out of .125 card. I sloted the first piece so the bridge could fit into it from the front. Put together looking at it from the front it forms a cross shape with the bridge section, dorsal section and the two wings forming the ends of the cross.
Next I disassemble the two parts and taking a file I file a slant on the wing so that looking at it from the front it looks diamond shaped. After that I have the basic shape of a deimurg ship. Last thing to do is to cut out very thin plasticard sheet, I believe it was .015 into the "deimurg" shapes. If you look at the forgeworld cruisers you will see that the surface forms kind of a ziggaurat of very thin sheet with an almost coastline effect. Like little island made of tiny squares. The bottom shape on the hull larger and the next levels smaller. After that some thin strips for the details everywhere else. I have a nice selection of styrene, pre-made rod, half-round and strip. Plastruct makes them but other hobby places sell it. I dished out a rod with a bur for the tiny radar dish on the front. The front curved pieces I believe I filed the front round and burred out the back. Don't really remember though.
After this I made molds and cast up enough for my fleet. I still have the molds so if anyone wants to buy some ships contact me. Its not much of a description, sorry, but my tech level is fairly low so even if I had step by step pictures, which I don't, I couldn't write on them to point out stuff anyway. Hope that helps. If anyone has any specific questions let me know.