Hello, I'm a ghost from the past (hello, and hope you're all well!) - one thing which may help narrow it down is seeing whether there is a problem with the display of models/textures outright, or if it's just a problem with the link between in the in-game item and the model.
If you go to the old "3D Tutorials and Links" (I assume many of the links are now dead - and all the images have long expired from imageshack or wherever they were hosted, sorry), there was some little tutorials from the times when we were testing things - some of them from before the models were linked correctly - you should be able to test armour/clothing etc by use of the ~param commands.
A lot of the setup info will be obsolete by now - but if you've already got a 3D server working, I'll assume you've got that bit sorted already. If you skip down to the Part One : Admin access and first commands bit, and try some of the param codes from there.
#1 Setting up 3D SDKPart OnePart TwoPart Three#2 Testing custom textures exampleAll partsYou're looking for bits like this:
Hats and Helmets
Hats and Helmets are on layer 154. This is again a model layer which sits above the base model. If you look in the #head section of the _FOHuman.fo3d, you'll see some of these hats contain a "DisableLayer 7" before the attach command (they probably all should do - the ones that don't are my error). This "layer 7" refers to 157, the hair. Consider layer numbers in the _FOHuman.fo3d to be counting from 150. This DisableLayer command is there to basically "delete the hair", so it doesn't clash with the hat or helmet. This will probably need thinking about in future, because we're going to end up with the old "hats make you suddenly bald" problem.
~param 0 154 z
For layer 154, the value (z) can be :
5, 6, 9, 13-18 (from main 3D repo)
26-34 (my own test stuff)
I probably can't be a lot of use right now, but once... a long time ago, I sort of understood how this all worked - and tried to write it all down in those tutorials. There was definitely a time where we could only add objects through param commands, because the grammar/syntax had changed in the SDK. Karpov did work on updating it at some point.
Anyway, if you can get armour/clothing etc to appear using param codes, the problem may just be in the file where models and objects are linked together (I apologise that I cannot remember which one right now). If models do not show at all, there is a problem... in a different file that I can't remember - but if you look back through posts by myself/Karpov/Graf/Gray etc, hopefully we discussed it on the forum at some point.
I wish I had clearer info to give you, but it's many years ago! I do hope you can make sense of some of this. I would love to see some of this work used for something.