There was just one Schweizer 1-23C built and it was owned and modified by Gehrlein. The aircraft was crashed and rebuilt with new 1-23D wings. The 1-23C's damaged wings were rebuilt and formed the basis for the Precursor. The fuselage for the Precursor started life as a 1963 model Schweizer 1-26A. The two components were reworked by Gehrlein and his two sons, Rod and Jay, in 1965. They took the 1-26A fuselage and mounted the wings from the Schweizer 1-23C, modifying the fuselage, which had mounted the original 1-26 wings in the mid position to accept the 1-23C wings in the high position. The resulting aircraft is registered with the Federal Aviation Administration in the Experimental - Racing - Amateur Built - Exhibition category.
The Precursor is of all-metal construction and features a fixed monowheel landing gear, with a small tail caster. Only one Precursor was built.
PIlot reports indicate that the Precursor climbs well in thermals and exhibits stable handling.
Gehrlein eventually sold the one-of-a-kind design to Les Stoner of Houston, Texas and today it is owned by Gehrlein's son, Rod, and based in Erie, Pennsylvania.