I thought that bowa's used cruel matriarch's of evisceration (something like that) and socketed them with 2x40/15. I think, i don't exactly know.
I don't know either which is why I'm asking 40/15s aren't commonplace as far as being traded goes on L East (most use them when they get them it seems) and when I do see one (or a 39/15 or something) its usually going for something ridiculous and more than it should be worth, so I prefer to stay away from them if I can.