I have been having much better luck at online auctions this year rather than local auctions/estate sales/antique stores. These pieces came from an online auction in Derry PA where the PHV/Westinghouse insulator plant was. The U-570 has some light spots in the glaze which will be more evident when it is cleaned better. The pinholes on both of them are so clean I'm not sure they were ever in use.

I'm not sure what the taller pieces in the back are, maybe transformer bushings. The bottom is solid with lines like threads on the outside. Inside the top, there is threading broken by 4 lines, and the hole looks to taper to the bottom, but it might be an illusion.