[Arran]

The factory parts list should list the Wattages, if it is a Philco Transitone, an AC/DC set, most of the resistors will be in half Watt sizes with maybe two or three two watt jobs. You can usually tell by the physical size, the smallest carbon resistors will be either 1/2 Watt or 1/4 Watt, use 1/2 Watts just to be safe, the larger sized ones will be either one or two Watts if they are carbon, each about double the size of the last.
Regards
Arran