The piece on the left is the EIN [050]. It is embossed: NEW ENG TEL & TEL . / CO. This is one with the oval blot out on the reverse side. I could not get a good photo of the faint oval marking. The right insulator is the EIN (that is, the embossing index number from the McDougald's Price Guides) [080]. It is embossed: NEW ENG TEL. & TEL. CO. Note the extra periods. This has a MLOD. See my previously posted photos of more CD 104 New Eng Tel & Tel pieces, starting here: [id=246373499]. Thanks for looking!