I was trained as an aircraft electrician in the early sixties on 1950s aircraft. An aircraft electrician would be required to know about any lamp on the aircraft, secret or not or else how would we test and relamp them? Yet I never encountered an Infra-Red lamp - though we did have Ultra-Violet cockpit lamps. These used a normal filament lamp behind a "U/V" filter and the lamps activated the instrument paint. The result was a dark cockpit with all visible lights turned off and only the instrument markings visible. Naturally, these lamps were referred to as "You-Vees".
The lights on the tail and wingtips were mostly navigation lights. When I worked on PA474 it had rear facing lights on the wingtips and these were referenced as "Formation Lights" They were dimmer than navigation lights and were on a separate circuit. We electricians understood them to be intended for night-time taxying and in the circuit; though for glider towing they might be useful for helping the glider pilot remain in position directly behind and slightly below the tug. The rear facing lamps on the deHavilland Heritage Centre Mossies appear to be these same formation lights.