Well, despite flu, adding extra solder and keeping the hakko at 450 degrees on the ground pin of the 440uF cap for a whole minute, the stub in the board still wouldn't budge. The 220uF cap on the other hand, desoldered painlessly at both ground and +ve ends. Oh well - it's now completely recapped and still functional

Have received the IXP-34-16 60mm silenx fan. Man this thing is silent, but I agree with JDW, it doesn't feel as though it moves as much air as the OEM fan (supposedly 18cfm vs 19cfm flow respectively), but it's not yet in the cage, so we'll see - perhaps that'll boost it a bit. It's a very easy hook up - it comes with a molex in-line plug (http://www.silenx.com/l.ixp-connectors.jpg) so it can be powered directly off the existing hard drive molex lead (and only draws 0.34 watts, so should be fine on the 12V line@ 0.028Amps). It's just a matter of desoldering the old fan's power leads from the analog board, which means the board can easily be returned to the stock fan in future if needs be as no wires need to be cut.

Now just waiting on my replacement seagate HD and 80->50-pin adaptor, and hoping it doesn't require termination!