Recently I got a Fostex X-26 multitrack cassette recorder.
This device was dirty and extremely dusty
Some channels didn't seem to work...
Tape had LOTS of wow and flutter
Overall it was in pretty bad shape
So I cleaned it, lubricated it,
fixed it, calibrated it, enhanced it
and solved the speed problem
Gave it a lot of TLC
It is now way better in every way
I will demonstrate with 2 stereo tracks
that I recorded (Dolby B is active)
on 1-2 Tin Pan Alley
on 3-4 Dire Straits
and mix them around a bit
sound is direct from the Fostex X-26

edit The wow and flutter problem is now completely solved, the tape speed is super tight now!