Olds Register photo guide –

Fullerton

Question 5: Serial number location

Olds trumpets and cornets (with the exception of the Mendez model) had the serial number stamped horizontally on the right side of the middle valve just below the leadpipe up until around serial number 425000.

All Mendez models and all other models after about serial number 425000 had serial numbers placed vertically on the left side (bell side) of the middle valve casing.