They can lease a/c, you know. The 744 is too big for the MAN BGI market anyway.
...and do you remember the furore it created when they put a Martinair 767 on the MCO run. The only thing close to the Virgin brand was the name on the fin.
I'm not sure VS would want to go and tarnish their reputation in the regions a second time by going down that route again; but funnier things have happened recently, so who knows....