[TR] Shift knob for overdrive cars

[Randall]

> There is this http://www.rimmerbros.co.uk/Item--i-GRID005712

But it requires a special shift lever, hollow and with larger threads.
Which they show as "No Longer Available".  That NLA "retainer" is important,
too, as the knob itself is not threaded.

I have the same setup on my Stags (as original).  I like the concept, but
can't say I like the execution.  That slide switch is somewhat hard to
operate even with bare hands, and practically impossible with driving gloves
on.  Since I can't feel it's position even with bare hands, I wind up having
to look at it every time to be sure it moved all the way.  (If it gets left
in the middle, the OD may jump in or out of gear unexpectedly, which I find
annoying.)

YMMV and all that
-- Randall