I've flown two-class 763s both between LAX and ORD and between ORD and BRU several times each route the last year and a half.

At first, up front I'd get seats where one of the controls was Lumbar, but the TV/audio/etc controls were unmoveable and there was no gooseneck lamp.

Then I started more often getting seats where none of the 4 controls was Lumbar (tho I forget what substituted).

I still got the latter Aug 18 flying out LAX-ORD-BRU.

But coming back on Aug 29 I flew in the back (exit row) BRU-ORD and for the first time the TV/audio/etc controls were removeable (a kind of "wired remote", tho you can't sretch it very far). Then I flew up front ORD-LAX and the TV/audio/etc controls were also removeable, and the Lumbar control had returned, but for the very first time I had a gooseneck lamp coming out of the seatback (in addition to the regular overhead lamp).

Are they changing seats that often, or am I running into different planes of different vintages?

Is it possible they used the same 763 for the BRU-ORD run and then a couple hours later for the ORD-LAX run? Or did they substitute (or redo) both planes between mid and late August? (I had previously assumed that on ORD-BRU they might keep running the same plane back and forth forever, since the schedule seemed to allow for it.)