And for all of those reasons, I have ordered one. I bought a class 15 for those same reasons too. There are lots of photos around of those cross-London freights with various non-Southern locos, including the aforementioned classes 15 and 16. I have been able to 'justify' buying classes 24, 25, 31, 35, 37 and 52 (just off the top of my head!) because of those wonderfully varied workings onto SR metals from other regions.