I don't claim to speak for anyone else, but I for one WOULD consider someone who in pre-vegan days purchased something non-vegan, as still a vegan now, even if they haven't gotten rid of said item, but don't contribute any more to the meat and by-products industry. I think it's all about trying, and being realistic. Personally, I have always hated leather sofas - they get hot and sweaty in the summer and you have to peel yourself off them. Plus I can just SMELL them!
I know what you mean about the unnecessary lack of labelling - it seems so pointless, and I really don't know why more companies don't do it wherever they can. Maybe they can't make a commitment to keeping that item vegan, maybe it's made on a production line where there may be cross-contamination. Maybe they think it will put off the rest of the consumers who see the vegan label and think 'eurgh, this is bound to be tasteless and bleurgh'. I don't know. Keep hassling them, I reckon!
Keep up the good work.