BEags,
I think that the Tornado to which you refer may have been ZD902, a highly modified F2A that was called TIARA (Tornado Integrated Avionics Research Aircraft). Much of the trials equipment was carried on the shoulder pylons in one or two modified German 1500l tanks, and sorties with them could be flown with or without underwing fuel tanks. We often flew it with 1500l fuel tanks on the inboard pylons but I cannot remember it ever being flown with 2250l tanks.
STH,
I seem to remeber that in days of yore the RAF F4 codes were A, B, C and D for 0, 1 (centreline), 2 (underwing) or 3 external fuel tanks. And for 'R' for the F3, perhaps the single underfuselage tank was on one of the shoulder pylons. I don't recall the F3 ever having a centreline pylon like the GR1/4 has (although I could be wrong).