Please note: "pF" (picofarads) are the same as mmf or mmfd (micro-micro farads).
"uF" is the same as "MF" or "MFD" (as listed in some older units), all mean "microfarad".
Nanofarads are 1000 times the size of a picofarad, and 1/1000th the size of a microfarad, eg: .047 uF = 47 nF = 47,000 pF.Nanofarads are usually seen in European equipment.
In old units, capacitors were usually made in increments of 5 , .05 or .005 uF. Later this was replaced by the "preferred value" system (where values are such that 10% tolerances just overlap). It's OK to replace, for example, a .05 capacitor with a .047, a .03 with a .033, a 30 uF with a 33 uF or 40 uF with 47 uF. In the case of larger capacitors (electrolytics) the original tolerances in old equipment was normally very broad (as much as -20 +100 %).