Hello again,
I don't have any experience of nickel plating, only zinc. Many of the forum members have zinc plating kits from Gateros, although others are available from the web. As with any finishing process (painting, plating, polishing) the key to a good finish is in the preparation - a bit like computers - garbage in, garbage out! Living in Orkney, I hate sending anything away, just in case it disappears in transit. It's a time consuming job but very satisfying when you see the results. Having a variable current/voltage stabilised power supply makes life easier but not essential.
There might be a re-posted piece on my site in the 'What's New' section with a brief account of how I do it. If you do need nickel plating, the processes are very similar.
Ian