The basic scale stock pin kit, which was produced by Campbell Scale Models, started out as part of the product line of Ayers.
As I recall, Ayers had a limited line of prototypical wood structure kits, reasonably priced, with easy to follow step by step instructions, which would afford a modeler and nice group of structurers.
The wonderful "HO Seeker" website, which is really a go-to place for anyone with an interest in an earlier era of model railroad supplies, has a suprisingly large number of Ayers catalogs and flyers. One that caught my eye was a page of scratch builders supplies because at some swap meet or estate sale I picked up packages of Ayers scale lumber, still good and straight and very fine-grained.
http://hoseeker.net/ayers/ayresscalemodelscatalog20pg06.jpg
Dave Nelson