Digital BW, The Print

I have borrowed a Macbeth TR524 CMYK densitometer, but I'm having
trouble trying to understand the values it reports in terms of color
shown in Photoshop. I'm trying to quantify the near-neutral values of
my inksets on Kayenta, but the density numbers that the 524 puts out
don't look anything like the various Color Picker numbers, for
example, my paper white reads as: C= -4.63, M= -4.79, Y = -4.54 and K=
-4.71. How can I use those values to plug something into the Color
Picker that makes sense?

CMYK numbers in the Color Picker must be positive values of no more
than 2 digit whole numbers, so the best I could come up with is to set
Y = 0 and put in the others as rounded-off percents: C = 1, M = 3, Y =
0 and K = 2 which gives me a reasonable-looking white of L = 95, a =
2, b = -2 or RGB = 241, 238, 243.

It is reasonable-looking, but is it reasonable?

I have the same kind of problem with the ink tones: if I subtract the
ink density readings from the paper white readings to get positive
decimal values and convert them to % CMYKs in Photoshop's Color
Picker, the tones look reasonable, but am I just screwing-around in a
color never-never land?

Thanks for all your help,

Frank