I've trying to repair an old cabinet tube radio. It appears to be early 30's from the dial (attached). There are no markings of make or model. The tubes in the radio are:
2 x National Union NU-57r
1 X RCA UX 280
1 X RCA Cunningham Radiotron with j14 stamped on the bottom (looks surprising like the NU-57r)
1 x Ken-Rad 2A5

Anyone have any ideas?

I can't even find any reference to NU-57r

The only marking on the metal is / 2 3 4

An NU 57 is a 57, a 280 is an 80, and so on (I don't know what the "r" means unless it's "replacement." The other tube might be a 58. You can try the databases at grillecloth.com or radiomuseum.org and perhaps find a match for make and model, though that's not a rare lineup, so there could be a lot of hits.

Alan,

Many thanks. Looking at the one broken tube, the R could also mean Registered as in TradeMark?

Unfortunately, I have no make and model for the radio. Since I'm in Australia, it may have been even made here in a local Sydney shop. Is there anyway one can even find out? It has three knobs on the front. One obviously for turning (0-100 dial), one for volume control and the third for???

You might put something in the title to indicate it's an Australian set, since there are a few such members here. I've never seen any markings for registered trademarks. Some makers used "E" for export tubes (but then, RCA put an "E" in the date code for "OEM", Original Equipment Mfr.

You can edit the title.

Very early on, the first numeric denoted the manufacturer, thus 145,245 etc was in fact a 45. "R" and "E"suffexes or prefexis could mean just about anything. If you can find or draw out a schematic by hand, we (probably my betters,) can help you get to the bottom of this.