The MT codes can be seen on these Rob Van Meel reprints, I have quite a few of these and they are very interesting, but each one generally only has a small section which is motor/cycle related.
The later editions of Orchard & Madden have some information about LV6 (Proprietary Spares) and LV7 (the vehicle manufacturer specific stuff). I'm not sure that I've come across LV8.
