(Sometimes the upper and lower ends of a keyboard have different date stamps, if two pieces of wood were used.) Triangulating using as many date stamps as possible (from keybed/balance rail, keys, transformer, speakers, volume knobs, and amp) will give you a pretty close idea, and usually (not always) the stamps on the wood will be among the latest dates. (Theorized because: Sometimes a single keybed is made from two pieces of wood, each with a different stamp at the transition point). The key stamp date is NOT the assembly date, but probably the date the keys were cut. Since no model of Wurlitzer was produced for more than 10 years, you can use this chart to get a general sense of the period of your model, then use the stamp on your keys and keybed to pinpoint it.This site can help decode dates found on transformers, speakers and volume/vibrato potentiometers. This used to be the preferred method of dating Wurlitzers, but these will generally predate the stamps found on the wood by a few months to even years:.(So far, data seems to be consistent with other clues.) (Year, and week of the year.) 2-digit stamps on keybeds may indicate the week of a given year, as well. The very earliest 140’s (and presumably the 145’s and 720’s) used different, 6-digit stamp codes.The year-digit ( Y) doesn’t include the decade so, a keybed will be stamped “ 4 05 23,” with the “ 4” meaning “197 4.” (I am pretty sure, BTW, that I am the first person to have cracked this date-stamp code among the people currently repairing Wurli’s.

It is not yet clear what those last “X” digits represent (perhaps an inspector/employee code, or a sequence or lot number).

The keybeds will often have a 5-digit code consisting of Y MM DD (colors my own.) The keys and main action rails will be stamped Y MM DDXXX sometimes a digit at either end will be smudged or faint. I had a Eureka moment recently, and figured out that, by August 1962 at the latest, all Wurlies used a consistent, cryptic date-stamping system for production of the keys, the keybeds (or balance rails) and the backs of the action rails (where the damper arms and hammers are mounted). You can date-confirm your own Wurli! Please do and send me the data, which will improve this resource.See Steve’s unprecedented online list of every model of Wurlitzer Electronic Piano ever produced, 1954-1983.

Wurlitzer piano age serial numbers