I was using the image to demonstrate aperture to somebody a couple of years ago. Here's the "stopped down" image for the uninitiated...
I "bought" (for a very small fee) the FT from my father around 1976 or so, after I got my first job. I shot many rolls of film through that camera. Mechanically, it still works fine. Can't get the mercury batteries any more, but you can get a reasonable facsimile (supposedly) to supply the meter.
Boy, that FT and lens look immaculate.
I think that when you get the replacement adapters (using, I think silver oxide cells), on some cameras it’s best to recalibrate the meter due to slight difference in the operating voltage.