I have an update for those who are interested. I found Contra 005 and installed it. It runs fine. Guess I'll play with it until I can get the new one working.
I'm running it on Windows XP, SP3. never had an issue when I've installed it in years past. Uninstalled when I cleaned the slate, but never got around to re-installing it until now. The game runs fine otherwise. except for the patch and the mod.
I should also add that I've uninstalled the game, cleared the directory so the mod isn't there either, and re-installed the game. I get the same error message as before.