If I was you Kev I would knock out all the core plugs and take the whole lot down to the nearest recon shop and have them hot tank it bolts and all. Probably only charge you £25 . That gets rid of all the paint,all the oil sludge and descales the waterways. We got a bupi here and anthing mechanical goes into that. Not as big as this one but about a meter square
http://www2.ppauctions.com/_assets/a...t_171_7859.jpg. Nooooooooooooooooooooooooo scrubbing
bob