Thanks Guys for your comments. David I know the Piko wagon has been used by many to represent the current Timber Wagons.
It is 57' 6" scale length and has 16 stanchions instead of 10. I suppose you could extend the body and rebuild the top deck but it looks a lot of work but it's worth considering.
Meanwhile I have down loaded the drawing of the 62'9" container wagon from the Freight Section but I'm having difficulty in making out the measurements. When I enlarge the drawing the numbers go blurry.
Can any sharp eyed reader tell me please help me with the following distances:
Over Buffers
Over Headstock
Over Containers (Deck)
Bogie Centres
Also where can I get more information on these wagons, my Oliver Doyle book of '87 only refers to Flat bogie Wagons Series 30501 -30540?