Japanese Sylvanias

[BrownSound1]

I was going through some some of my father's old tube equipment and decided to crack open an old Akai M7 reel to reel deck that he bought in 1962. Anway, I noticed that it had a 12AX7 and a 6BQ5(EL84) in each channel..so I pulled them, and they say Sylvania, but I found "Japan" silk screened on the glass. Anyone have a clue if these are worth using? They are pretty old, because I cannot remember him changing tubes in that thing, and it was hardly used from the late 70's onwards. Just puzzled me about them being Japanese tubes. I'm more interested in the 12AX7s than the EL84s. I'll try and get some pics.

I also found a bunch of Raytheon 6EU7s, and an ancient wooden Silvertone radio. The radio was my mother's parents radio, and she said they had that when she was really small. Most of the tubes in it say Silvertone...so I'm guessing they came in the little radio. If that is the case they are over 50 years old...and still work.