Be careful with that great radio---don't think I'd let one as nice as yours out of the house !
I take my antiques outside all the time; they like showing me what they got AFA peformance, expecially at night, lol.
Good to hear about the battery---wonder how long it will actually last ? Keep an eye open for any seepage/leakage !
The battery should last a long time. These types of small signal Transistors consume zip for current, as opposed to tube filaments.
One good point about this set, is that the battery is inside a metal holder, keeping it isolated from the circuitry.
Three 1-1/2 volt triple A's can also be used to power it, which is what I do, being too cheap to splurge for a real 4 volt battery, lol.