You did well!
I first tried for a bew litter back in 2009-2010 and wound up with MC. I used a blazed and husky.
My whole litter had it.
So far, I'm at generation 3 and everything is going great, knock on wood!
So far, I've noticed blazed might be to blame more-so than just plain high whites. I think it also depends on how you're making high whites. Maybe using hooded rats, or other rats not known to carry MC is better?
I want to get some c/c bew and make some be siamese<3
That litter is all BE. But They are marked so I don't think they are considered BEW. BEW is all white with black eyes, no?