"Matching numbers" is a term that car collectors use to describe a car on which all the parts – body, engine, rear axle – have proper factory serial numbers. The classic Corvette owner who spends six figures restoring a car with an engine code that doesn't match the chassis number is probably the type of person who’s waiting to sell his Tucker stock at a higher price. In other words, the dollars spent on the restoration may be a bad investment.
Almost all motor vehicles, from the earliest ones built, have “patent plate numbers” or “serial numbers.” These Vehicle Identification Numbers (VINs) describe in what sequence the car was built – whether it was made early in the model year or toward the end. By the 1920s, vehicle identification number (VIN) systems became quite sophisticated. In addition to a serial number stamped in one or more specific locations on the vehicle itself, cars and trucks had unique engine numbers, casting numbers, parts numbers, option codes, paint codes and interior trim codes.
Let’s examine interior trim codes to see how code numbers work. Through the 1930s, most automakers offered a limited number of interior options. A sporty roadster might have been available only in tan with red wheels and a choice of brown cloth or brown leather upholstery. Sedans were generally offered in dark colors with taupe or gray interiors. Corduroy was usually the standard interior fabric while deluxe interiors were done in broadcloth or mohair. Station wagons were usually painted tan or brown with matching imitation leather upholstery. By the late 1940s, even low-priced cars like Chevrolet offered many more upholstery codes. Twelve different coded choices appeared on Chevrolet's 1947 factory Trim Combination Chart.
The 1947 Chevrolet Trim Combination Chart was relatively simple to understand and use. However, by 1957, Chevrolet was offering 49 different two-tone combinations. That made the list long and complicated. By the 1960s, most manufacturers were selling compact, mid-size and full-size car-lines, plus a sprinkling of sporty and specialty models such as muscle cars. Interior options were up into the hundreds by that time. This widening of choices was great for people who bought these cars new, but it can be a headache for collectors today.
It’s not uncommon to find that an old car has been repainted a non-original color, with its interior changed to match the new color. If a car is not restored to match the color codes and trim codes stamped on the data plate under the hood or on the door jamb, it could affect the value of the vehicle, especially if it's a Corvette, Thunderbird, Mustang or muscle car.
Another important thing about trim codes is that companies selling reproduction interior kits use the factory trim codes to identify the proper kit for a specific car. These kits can cost thousands of dollars. Before calling to order replacement interior parts, the old-car restorer would be wise to determine the proper trim codes for the car being restored.
Although not impossible to find, for many years factory trim codes and other vehicle identification numbers were not readily available to most car collectors. They appeared in certain types of factory literature, such as "Master Parts Manuals" and "Assembly Manuals" that did not have very wide distribution to the public. "Owner's Manuals" and "Work Shop Manuals," which were printed in larger quantities for the public, do not show factory trim codes. Sales literature, which most old car owners collect, may show drawings or photos of a few interiors and pictures of fabrics, but not the factory trim codes.
Luckily, the VINs that most restorers need are now included in a series of books compiled and by the editors of Cars & Parts magazine. These "ID Number Books" are easy-to-use guides designed to help collectors of post World War II cars and trucks decipher VIN codes and trim tags to determine the where their vehicles were made, engine sizes, paint colors and upholstery combinations. The "ID Number" catalogs can be ordered by calling 1-800-327-1259 from Ohio or 1-800-448-3611 from other states or, from outside the United States, by calling (513) 498-0803.
This article is by John “Gunner” Gunnell, automotive books editor at Krause Publications, Iola, Wis., and former editor of OLD CARS WEEKLY and OLD CARS PRICE GUIDE