As far as original-issue AMT truck kits go, the rarest of the breed probably was the Richard Petty Ford LN-series "wedge race car hauler'/Dodge "kit car" modified stocker in Petty #43 trim.
Apparently, AMT tried to slip this one in under Petty Enterprises licensing they had back in the 70's, only to get shut down on it very quickly when Petty Enterprises found out. Only a few thousand kits ever made it into customer hands as AMT Corporation had to do a recall on the kits (Petty was running Olds Cutlass HT's at the time). I have three of the kits, still sealed, as received back in 1977 or 1978 as complimentary kits, for being part of AMT's group of box art model builders.
Of course, organizations such as the American Legion, Veterans of Foreign Wars, The 40&8 people, and of course, the Shriners, all these organizaitions have had chapters who were altering the wheelbase of Model T Fords as far back as the late 1920's, to perform wheelstands (often extended for several city blocks) in parades and at other public functions. Does that count?
Brick and Mortar hobby shops will continue to survive as well as thrive as long as they are well-capitalized (meaning they are able to have and maintain a well-stocked, comprehensive inventory), understand, live and breath merchandising, and pay attention to their bottom line.
For what it is worth: Ford's Iron Mountain wood-product factory used two types of wood on 49-51 Ford and Mercury woodie station wagon body panels: Hard maple for the framing, and Honduran Mahogany for the molded plywood "panels". The Mahogany has a fairly straight grain, typical of most tropical hardwoods, that is fairly visible even in 1/25 scale. The maple used for the framing, on the other hand, is a very close-grained wood, meaning that the grain isn't all that visible even in 1:1 scale, due also to its being a very "blond" wood, without much color to it. While maple grain can be made to show by staining it, when finished blond with a clear varnish (which is what Ford used throughout the years of their woody station wagon production (1929-51), they did not stain it. Over the years, many restorers and street rodders have built reproduction woodie body shells, and intent on "effect", they've stained the wood; some have used curly grained maple (which Ford did not use) while others built their replacement framing from oak, which was almost never used in wooden station wagon construction, maple being by far and away the industry standard back in the day.
While Ford woodies, from their introduction in 1929 through the 1948 model run, were built using cabinet-making construction and techniques, the '49-'51 station wagon bodies, due to their now rounded, curved body panels, were made by laminating thin strips of maple in molding presses to give them the required curvatures to match the shapes of the molded plywood (birch with a mahogany veneer on the outer surface) panels. This meant that there was virtually no milling done, except at the ends of some framing sections that would have exposed the end of the grain. Thus the grain of the maple, on a new '49-'51 Mercury or Ford station wagon was not readily visible, and in 1/25 scale would be nigh to invisible. The Mahogany grain would have been seen though, but it would be fairly straight, with virtually no knots or burling present.
The pic that Casey Littman put up is actually quite accurate: You can see the subtle mahogany grain, but barely a hint of the grain in the maple framing.