Flintlock, two more suggestions about improving your great mod:
1: The "local no-tech-req" resources are working fantastically well.

They are working so well, that for my mods (CCM 2.6 and RARR) with thousands of units in it, they are the much better option compared to the option, that a unit for its production needs a special building in a city. Creating a "special resource", that is available only in a city with a special building and setting this resource as a prerequisite for several hundreds of units in the editor needs much less space (and work) in the default.c3x_config file, than to list hundreds of units that need a special building in that file. With the fix of the ghost resources bug in your mod (not yet tested by me), this seems to be the much better modding option for mods with lots of units in it.
A small problem with the "local no-tech-req" resources seems to be, that I was not able to create working
"special resources" with two or more words for the resource. Per example at present it seems, that this option in your mod is not accepting a resource named
"Electric Power", but it works when that special resource is named
Electricity. For resources with two or more words (like Electric Power) even to set them in quotation marks was not helpful. If there is a special resource with two or more words in the list of the default.c3x_config file, the complete list for that option was ignored, even without giving a warning about a not appropriate naming of those resources.
2. The icons for veteran aircraft and veteran ships:
The AirandHarb icons in the Civ 3 city folder are connected to the in my eyes not so important tradenet functions of buildings. Both the harbor and the airport, have double functions for producing veteran air- or seaunits and opening sea- or airtrade.
In my eyes it would be much better, if those icons could be used for the veteran flags of those buildings for producing and upgrading sea- and airunits, as in the game, at least for me, it is much more important to see where I can heal my ships and my planes in one turn and upgrade them, than to know if this is a location in the tradenet, especially as in many scenarios there are deep cuts done in that tradenet and therefor here the use of these icons is mostly wasted.