If anyone's still interesting in repairing this, I believe that all the relevant models are available in the Europe 1940 mod here: https://steamcommunity.com/sharedfiles/filedetails/?id=493646180 (it was updated in September 2019). I guess it would just be a matter of painstakingly plugging in the new URLs for each individual piece.

You can do that, I setup TTS to chache my images to my documents and then I use TTS Mod backup to force the download of all the pieces before I play the game so its much faster.

Yeah, it seems like an odd choice to have things "download" to you everytime you load up a game. I'm not 100%sure how TTS does it but I would like the option to have it download to your pc and then link locally so this sort of thing doesn't happen.

ive noticed all axis and allies games seem to be having trouble. maybe theyre sharing all the same pieces

http://steamcommunity.com/sharedfiles/filedetails/?id=962922133

Here is a link to a quick fixer upper I just did. It uses basic game shapes to replace the missing unit models. Unfortunatly I don't have the time to replace the missing order card textures but I plan to do somthing about that in the future.

I've just checked. Seems the custom models for the units aren't loading properly. Probably check with the original uploaders of the D-Day game too see what's happening.
http://steamcommunity.com/sharedfiles/filedetails/?id=457481922&searchtext=d-day

any idea why its not working?

I've updated it by placing missing units on the US and German reinforcment sheet and removing one German Infantry that wasnt ment to be on one of the beaches. I've also unlocked the block houses and turned one of the 88s the right way up. I also noticed that the order card deck was not in the correct order so I have made two decks. One with just the normal orders, and another including both Fortune and Tactics cards.