Because there don't seem to be any solutions to my problem in the
consumer electronics realm, I'm hoping one might exist in pro land.

As everyone knows, audio cassette deck heads normally can only be
adjusted for azimuth -- by twisting the left screw on the head (the
right screw merely being a fixed support screw).

Unfortunately, I have a box full of audio cassette tapes recorded
long ago using a Sanyo deck whose head wasn't kosher in terms of
*horizontal* alignment. As a result, when they are played in any
other cassette deck, no matter how much I adjust the azimuth screw,
the frequency response curve is very flat. Visual example:

http://img73.exs.cx/img73/6549/cassette-response.gif

In order to properly track these tapes, I'll obviously need a deck
whose head features TWO adjustable screws -- i.e. where I can twist
the left AND right screws to achieve proper horizontal alignment.

The problem is, I don't know where to find such a deck. Suggestions?