The info from AMSOIL is useful, but they are not well represented in the UK. However, a well respected British company, Millers Oils www.millersoils.co.uk
have recommended two of their products. They have representatives in US and around the world.
Classic Running In Oil
Liquid Glaze Bust
I'm going to try the Liquid Glaze Bust, as I've covered 12,000 km since the rebuild. The Classic Running In Oil sounds ideal for first fill after a rebuild.
Millers have confirmed that both the above products are suitable for wet clutch engines.