High Voltage Capacitors and Resistors for Antique and Vintage Radios: 

Just Radios

This couple in Canada do a nice job. They are helpful, friendly and the items arrive in good condition. They sell all types of capacitors including kits that include all the typical values one would need for a restoration. They also sell schematic diagrams for antique and vintage radios. []

General Suppliers:

Radio Daze

These guys have a large selection of parts and general restoration needs. They sell bulk dial chord and have a decent selection of grill cloth. Additionally, they stock some of the detail parts that make a restoration really special, such as knob felts etc. [ ]

Antique Radio Supply

Another supplier with a good supply of the typical parts needed to restore an old radio. They also stock guitar amp parts and accessories.[]

Renovated Radios 

Here is a site that features articles, radios for sale and a large selection of parts such as knobs and escutcheons. []

Oppat’s radio parts

You can get a decent selection of Philco dial reproductions here. []

Phil’s Old Radios