[Ron Ramirez]

If you want to use a direct audio input, I can only see two ways of going about this:

1. Continue to use your phono input as an auxiliary audio input; or
2. Modify the radio to use an audio input jack and perhaps a switch in back of the set, or use a 1/8" jack that will break the radio's audio at the point of contact and automatically switch to the phone jack input when a plug is inserted into the jack.

There would not be an easy way to use one of the set's AM preset pushbuttons to accomplish this without making some serious modifications, which I do not recommend.

Regarding your 42-1015 pushbuttons: I'm afraid I can't comment on those as I have yet to restore my 42-1015 chassis. I did notice when I bought the set how its pushbutton assembly is quite different from lesser 1942 Philco models.