I feel lucky I was able to acquire these 7 beauties from a decent sized collection of various insulators advertised for sale on the Internet. The two tone blue and mottled blue U-610A's go great with the rest I have. I've been looking for some lighter blue Ohio Brass marked U-501's for a long time. The U-611B has a nice glaze on it. The yellowish one is a U-448 I believe