If the r2lc has unique code, you can still get it. You would need to contact lionel. They can burn the correct code into the r2lc. My whale aquarium car had a r2lc that went bad. It had whale code. Lionel programmed a r2lc with the correct code for me.
A friend of mine has the missile launch set. His engine had the r2lc go bad. I put a new standard r2lc08 in. Works perfect. Not sure if the army version is different.