Chris, filter complete is LV6/MT1/AU/LK/30319, element only LV6/MT9/AU/LK/MF56A. The Avery coupling complete is LV6/MT9/AU/LK/AVA51E, LV6/MT9/AU/LK/AVA54E is the bottom half and the top part that fits to the tank is LV6/MT9/AU/LK/AVA1153E, the aluminium union that holds them together is LV6/MT9/AU/LK/AVA62E. I've not found an old tank yet with a top coupling that reseals, though the bottom half of the coupling always seem ok. Bottom connectors also available at Green Machine Surplus.
Simon