This is a helpful post. I flew the 601-3A (actually the very first 601-3A delivered) for about 7 years. 3-5 times to Europe annually. I do not believe the collector tank is internally separated into left engine/right engine feed. For sure there are 2 separate fuel lines, actually 3 including the APU, from that tank to its respective engine but I believe the collector tank is but one tank feeding engines and APU. I could be wrong but that's how I recall it.