Mic positioning is part skill, part art.. & also part guesswork.
I could tell you that you need the mic approximately 6" above the bow, 2ft in front of the strings & pointing at an ƒ-hole... but that's just because that's where it gave the sound I wanted last time I did it - in a different room with a different mic & a different player on a ...
The speed may vary (and actually you may even see differences between units of the same model). If you know the tuning, chords etc you can always go through a computer and resample if you want pitch to be perfect.
You can use Sony - Sound Forge for precise pitch-shifting with curves if your problem is a problem with the tape recording speed.
To note that pitch-shifting if no time-stretch is added to it doesn't significantly alter your original sound quality it will only change the tone.
Steinberg - Cubase's tool seems pretty accurate too.
Also, Ableton - Live and ...