Tomb, depends on the year and trans type, need to state specifics - but might try here - or maybe here scroll down to #1964 - and there's other speedo repair services that might have them
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics