OK Guys, heres a section I've just done. The top stones in in the walling were all incorporated in the same batch of cement as the track base.So makes for a very strong over-all finish. OK first the timber was cut to the desired length then nails hammered in. Then the wooden strips are bedded in the cement nailed face down and then levelled.Then more cement spread and tamped in to shape,finally a few handfulls of fine crushed grey rock/rockdust is spread on top and tamped into the cement to shape. This gives a nice ballasted look to the track and also being tamped into the wet cement it stays put. (Incidentally the sand I'm using for the cement is is rough/coarse grade sand ,not fine building sand used for brickwork.When I finally lay the track more of this fine crushed rock will be spread and brushed in between the sleepers (ties in US-speak). See stage by stage pics attached.