I'm not criticizing your work, but would it be possible to just model new nacelles? Better than kitbashing models together. P81's connie is older than most, and has been outclassed by newer TMP models. If you made your own, you could even do it however the heck you wanted and not have to follow a standard design.
AGain, it leads back to the simple fact: Nobody did. Or atleast nobody willing to let their stuff be bashed, or without exsessive strings attached, or ending up with something with an excessive number of tiny textures, or soemthing that simply doesn't match the rest of the gafy textured ships. This leads to needed to redo the whole set of textures and trying to convince someone to do it, and rebashing all those variants. Honestly, such an effort of convincing people to work on it and then those people actualy putting the work time on it would be better spent on something more worthwhile than a connie or miranda bash. We have nothing in the way of decent sona, or most detla quad races and other such things, sf museum ships, and lets not forget all of those fan designs floating around that everyone wants to worship the author for creating but never seem to get built. For the connie and miranda itself, sure, lets get a high quality canon one made. But all those bashes, some of which people complain as being silly and fanboyish...I'm not sure it's worth redoing them all.
If someone who's willing to allow bashing wants to make the connie, miranda, oberth ect in high quality and bash compatable, hey great, toss in the excel too and maybe we can get down to bashing the dozens upon dozens of bashes we all have currently with the new parts. it'd probablt take a team of a dozen bashers months once the parts are made to do it but it could be done. But wouldn't the time better be spent on somethign else?