In regards to the curiass,
I think I solved the problem. I installed a new copy of COAS on my hard drive. Enabled beta mode and started a game. Sure enough there was the curiass.
So I copied over the original itemsint into my modded copy of COAS and started up, and there it was.
So now I know the problem was with the itemsint file, where exactly, I don't know but I'll add some new items then test it again, if it works I'll confirm that this bug has been squashed
Update:
I need to test this further, but from what I'm seeing, there might be an item limit which would explain why the curiass was disapearing.
The reason why it was the curiass and not something else is because it's last on the list of items.
I added a new item, started the game and expenssive curiass was gone. I exited, removed the new item, started up again, and there was the curiass again.
If indeed is the case, that would be bad news for future items since it would have to replace an item already in the game.