Just a few 1930s adverts, print onto a sheet of A4 label stock, cut out and stick around the layout. This image has been downsized to get inside the forum size limits, the original was nearly 10Mb.

I searched the web for images of old ads and downloaded as many as I could; a lot were pics of original signs rusted and chipped, I used a photo processing app to clean them up and resize them to be suitable for N gauge. I have resized most of those on this sheet for ease of viewing here. I do have a few more, but having resized them I ran out of room!

The Strong Country ones I did myself, found a pic of  Lord Nelson in 1930s livery drew the sorround, added the text then added the train after making a few changes,  added headcode discs, altered sky and ballast colours etc. I actually wanted a pic of a King Arthur on a train similar or same as the Nelson.

If anybody would like a copy to play with (e.g resize to your scale)  send me a PM with your email address and I'll attach a copy, alternatively if you use Skype my Skype ID is in my profile send a contact request, - transferring files on Skype is much easier and quicker, it would also be possible to send individual ads as larger images which are easier to work on. I'd advise working on images of each ad on its own, it may take longer but you can tailor them to suit the space they are going in.  You can also put as many copies of each ad as you need, and maybe need different sizes of a particular ad. I'm tweaking some to go on buses. Some would also have appeared on larger hoardings as well as the enamel versions. If you Google "old adverts" some sites even quote the dimensions of the originals.

To separate an individual ad from a sheet mask it (or whatever your photo app calls selecting part of an image), copy then paste as new image,

A further tip, if you visit any preserved railways they often have some on stations and lineside, take  photos and add them to your collection!