MOTM

Dear all,

I am contemplating my 3 soon-to-arrive 300 kits and have long thought
about implementing Paul Haneberg's Tracking Modification in the
process of building them. 
(http://www.wiseguysynth.com/larry/mods/VCO_track.htm)

Like Paul I'm afflicted with perfect pitch - well, extremely
discriminating relative pitch, anyway - and I record melodic acoustic
/ electric music.  So being in tune makes all the difference,
expecially when dealing with acoustic instruments.

Now - I'm admittedly a somewhat smart idiot, OK?  I mean smart enough
to get myself into trouble and I'm still relatively inexperienced with
these exquisite MOTM things so please forgive my continuing stream of
stupid questions.

In Paul Haneberg's description of the Mod, he describes replacing the
300's R50 (which has a standard value of 2.2M) with first a 2M, then
eventually with a 1.5M.  

It has occurred to me that rather than replacing R50 with these - one
by one - maybe there's some gadget - variable between - oh - like 1.2M
and 3M... which could be put in R50's slot and then adjusted with a
little scew or something.  I thought I'd seen little things kinda like
this, but I'm not sure if one could be gotten that would work here. 
Is there something like this?

OK - so - if such a thing can't be gotten, then is there some way that
the R50 could be clipped into something rather than soldered... So
that the adjustment could be made by snapping the resistors in and out?

My next question has to do with Larry Hendry's 300 VCO fine-tune-range
modification. (http://www.wiseguysynth.com/larry/mods/300mod.htm) 
This is attractive to me as well because I anticipate accurate tuning
will be inportant given my application.  Anybody have experience with
this Mod?  Comments?

Thanks so much, everybody.

wjhall