The method for those who are interested, I first cleaned the pickup with some soapy water and wire wool to get a good shine on the poles (be sure to wipe away the filings which have stuck with a cloth).
I then placed the pickup with the poles facing down onto the centre of a dessert plate. This is because as it has a slight shallow curve and the gold plating solution can accumulate in the centre.
I then pipetted about 5ml of my gold plating solution till the solution adequately covered the poles and was just
up to the bobbin (you wouldn't want this solution getting inside the pickup). The solution I used was 5% potassium gold cyanide (be very careful, highly toxic!)
I then plugged in a power supply and set it at 12V. I hooked the anode (-) up to a carbon rod and sat that in the solution next to the pickup.
I then touched the positive terminal onto the underside of each pole essentially making the pickup pole the cathode. During this process, aqueous gold cations (Au+) from the solution are attracted to pickup pole where they are reduced to solid gold by gaining an electron. The reaction also gave off hydrogen gas (an indicator that plating was happening).
I spent about 2 minutes on each pole before moving onto the next one and it resulted in a fairly decent coat of gold (it didn't rub off when I wiped it with my finger). I wasn't too worried about making it too thick as they're not prone to getting worn (after all, nothing will be touching them).
After plating, I then wiped the pickup dry using a paper towel and cleaned it again with water as it still had traces of cyanide on it and wanted to ensure it was clean
It goes without saying that I did all this wearing gloves, in a very well ventilated room and covered my working area with newspaper in case there were any spillages. Be very careful if you aim of attempting this yourself. On the bottle I used, the gold plating solution stated "fatal if in contact with skin"!