If it is a digital from the 40's, don't try. Barr digital clocks are somewhat uncommon and even more uncommon in good working order. Barr's mechanism was unique. The wheels were metal and they interlocked via gear teeth on the inside of the wheels. If you dissemble a set of Barr wheels, be prepared to spend an evening trying to reassemble them in proper orientation. Even with proper assembly, the Barr mechanism had difficulty positioning the facets of the wheels so the numbers lined up properly. Russ.