Just a helpful tip, if you use flux use a non corrosive 'no clean' flux and a high quality resin core solder .
http://www.jaycar.com.au/productView.asp?ID=NS3036&keywords=flux&form=KEYWORD

some gel type fluxes are very corrosive and after a year or 2 will eat there way through the crimp contact and with the help of some heat, seep down the pin header onto the board and cause corrosion damage on all items involved.

What makes it worse is that some gel fluxes are conductive and if they seep across 2 different power circuits it can cause an arc or leakage form one circuit to another. I have seen this happen in many extra low voltage circuit (25 volts RMS or less)

I always solder the replacement crimp connectors on high current applications and often use a non corrosive non clean flux,

I mean no disrespect to anyone here, and i am assuming they are referring to a non corrosive non conductive flux but I just would like to help those of you who didn't know about the difference in properties in different brands and types of flux.

Another thing I would like to point out is that the majority of tin plated headers and crimp connectors that are used on pinball machine have a maximum life of 25 cycles (I.E after the header and pin has been plugged in and removed 25 times as far as the manufactures are concerned it needs to be replaced). This is not much of a problem on low current circuits like switch rows and columns, but with high current circuits like G.I. circuits you may start having problems.

I know the difference between fluxes , i've been repairing Pinball boards for many years and i only ever use Kester non corrosive ,non-conductive flux.....but  your in-depth explanation may be helpful to others.