Old Tube Radio mod question

Is it possible (and if so, has anyone done it) to add a "Line In" into an old tube radio so that it cuts out the reciever circuitry and uses the amplifier circuitry?

In other words, is it possible to mod an old radio so that there's a 1/8" female jack in the radio chassis that I could plug an MP3 player into that would bypass the reciever but still use the volume and tone knobs on the radio?

Radio in question is a '54 Chevy if it matters. I can't see why the amplifier part couldn't work, even if it meant permanently losing the reciever.

 

There's a thread here that has a schematic for doing this. Try search function.

 

I've been searching all day, but only came up with iPod direct wiring stuff and new amplifiers wired to old speakers and that sort of thing. What should I be using as my search keywords?

Edit: Ha! Nevermind - I just found it. Thanks!

 

Yeah it is.
Don VE3LYX (other kinda HAM too)