Just a fresh appeal on this.
If anyone has even a bare casting in serviceable order I'd be very grateful for it.
I sincerely hope it doesn't come to this but if I can't sort the cooling issues with the spare 12 valve engine I've installed in Frederic's car then I'll have to look at rebuilding the engine which failed after only 250 miles or so of gentle use. Only I'll get it done by someone who knows what they are doing this time........