Hi Stu,
If you can find it, I did a build diary with a Wilkinson tele bridge on my ash tele. Its a little shorter than the PBG bridge so I had to fill the existing predrilled bridge holes and measure the scale length with the neck on to mark out the new bridge holes. Make sure you check the bridge is centered to the neck etc.
As a rule now, I do all modifications to the guitar before I start sanding or doing any finishes. I have found that even changing little things like the pots or the switch require some fiddly changes to the kit. Not difficult, but its better to sand out any dings or clamp marks only once.
When i did my tele I did the whole thing and played it before doing any finishes just to make sure (cos teles are cool like that).