Well some of the 4 lamp T8 ballasts I replaced was dating to 1997!!! Took out one that was from 1996! The lamps that still works, some are older than 2003, as they did not have the "Hg" logo!
The ballast that was in this thing shorted itself to the case. (You can see the ballast in there.) It wasn't working right so the gull pecked and pecked on it until sparks came out one corner of the case. I might be able to fix it. Solder around one of the part went bad. One time it got hot and it melted a hole in the insulating plastic and ended up shorting out by the gull's pecks.
It was totally out in the first place...so I did a test to confirm what was the problem, and after making a sudden move, it flashed, so I pecked it (at first with my hand, then the handle of the screw driver) it kept flicking on for half a second, and hit it again and did same thing and I did it over and over and over......until a small spark came out of the corner....then it would do no more!
It does look like a T12 fixture channel. At least with striplights and wraparounds the sockets have wider spacing if they're made for T12s than those made for T8 from day one.
Not always....and most were T8s from.day one assembled a factory called Mobern Corp which is just 10 min from my house!...we have had some T12 units in the same place but they were in different make troffers, not made by Mobern.......in fact two troffers with T12 only held two lamps but I converted them to 4 lampers.....I reused the remaining T12 ballasts in a different room where softer light was desired.....