You would have to create two extra meshes to carry the attachment point for the ACS hoses/couplers at each end of the loco. If you are going to go to that trouble you might as well make the loco full ACS, but then of course you would have two couplers/hoses at each end if they are part of the loco mesh...
Ideally the original creator would remove the coupler and hoses from the mesh, add the ACS attachment points and write a script to control them. It's not that hard to do, but of course it's extremely unlikely to happen.
Paul