The Fisher Treble and Bass knobs needed for the Philharmonic V Model P-290

[soundstar1]

Hello does anyone know where i can buy the replacement treble and bass knobs for the Fisher Philharmonic V Model P-290. please see the screenshots below

https://imgdepot.net/image/Fisher-Philharmonic-V-Model-P-290.I7nFj
https://imgdepot.net/image/Fisher-Philharmonic-V-Model-P-290.I7UIH