Nice. Good luck mate. If you are going to take it bacjk to bare metal and derust, may I suggest
http://www.surfaceprocessing.co.uk/.
£750 for the alkaline->hydrocarbon->hydrochloric acid dip and then
£750 for the The Electrophoretic Coating.
This is what I'm going to do to my S15. This will save tonnes of time and also does not work out bad price wise as you save on not havin to buy expensive stuff like deox-c, sandpaper, shotblaster etc etc etc.
Anyway, good luck. I'll be following this with interest.