Ah well, the box now has a mixture of:http://www.camskill.co.uk/products.php?plid=m1b539s1733p6951&rs=gb (as I had some lying around), and this: http://www.commaoil.com/productsguide/view/6/182, again, because I had it lying around. If it all goes horribly wrong, you guys will be the first to know. So far though, there has been a marked improvement. I took my father-in-law out in the disco for about 5 mile round trip just local country lanes, about three quarters of the way round, I'd stopped thinking about the box altogether. It was still a bit graunchy when I first set out, but there's a big difference. The clock says 126K on it, so I suppose with a bit of towing and so on in there, the gearbox maybe feeling a little tired by now.
If the oil isn't quite right (and I know it should have MTF 94 in it), it has to be better than what came out - that was a slushy brown colour - looked like water in the river thames, or what happens when you make 50:50 orange juice and cola...
It'll be interesting to see what it feels like tomorrow morning when it's cold - I warmed it up to make the oil flow out nicely...
Ben