Not sure about the reasons behind MAN-MCO getting a 400 recently as I've been away for a couple of weeks. I can only assume that TF-ATN was tech or something and TF-ATW was unavailable as it's on maintenance. A LGW based 400 would be the obvious choice to cover VS75/76 due to having a higher seating capacity than the LHR based a/c, but I guess it's just (bad!) luck that you got VGAL twice.
There's nothing wrong with G-VGAL....I think David was intimating that he would've preferred 2 different VS 744's to visit MAN rather than the same one twice (ie from a spotter/enthusiast's perspective).
Absolutely correct! I've never been to LGW and the last time I went to LHR, VS had 1 747, therefore, one is reliant upon "misfortune" to strike or unforecast inclement weather so that unusual aircraft grace the tarmac up here!