You're probably just as well off without the instructions.  Some of the kits of theirs I've built can't be done if you follow the instructions as previously assembled pieces prevent you adding others.  If you leave the roof off you can slip a block of wood inside it to rest on while you solder the strapping.  You can probably find better castings from other suppliers now and I've usually found there are plenty of extra details you can add if (as you have) you have decent photographs.  

I haven't built a GW kit of theirs, but the LNER ones which I have are often the wrong height and I've ended up replacing the W irons and brake assemblies.

I hope you've got good info for the chassis. I can't think of a book that has any particularly good photos to help.

Good luck with the build.

Mike

I wouldn't say a Falcon Brass kit was 'easier' - I attempted one as my first brass kit many years ago (ie prior to current ownership) and it was a total disaster, and was left buried at the bottom of a box of "stuff". For some time I put it down to my ineptitude, but having been enlightened by other club members, tried a couple of other etched wagon kits, and found that they weren't that difficult. I recently found the original kit, and realised that it was predominantly the kit that was poor - being asked to fold up the sides and ends from the floor with no etch lines and with no chance of two of the corners actually ever meeting.

I found that the 5522 model beginners wagon fret (now sold by Lochgorm kits) were a pretty good "lesson" - cheap enough to not worry about too much. Comet are a good starting point for coaching stock, as the sides come pre-rolled and I've found the parts just fit together. I haven't tried London Road rolling stock kits to be able to compare.