Try your local Ham Radio group, someone may know an 'old-time' tech. Or look for Antique Shops that specialise in old Radios, they will have a Tech they send radios to.
Hi There, NOSTALGIC WIRELESS COMPANY, 63 Silverdale Rd. Eaglemont, 3094, Victoria, Australia. (03) 9499 2495. (that's in Melbourne) They repair/restore all types of valve car radios, AM/FM conversions, Guitar Valve amps, Domestic valve radios, Gramophones, you name it. sales@nostalgicwireless.com.au Regards, Kevin.