Yes, I've done this. I don't have a tutorial or photos, but basically I just located the decoder, a keep alive, and a speaker in the tender. Hooked the decoder up to the pickup strips in the tender for power, and routed wires forward for the motor and headlight. You'll need to isolate the motor from the frame; I didn't try to run pickup wires from the boiler frame back to the tender, since I found that the combination of tender pickup and a keep-alive (I think I used a TCS KA-3) was sufficient to avoid any electrical problems. The speaker was an 11x15mm in a custom enclosure mounted transversely in the front of the tender; everything else went behind the speaker. I also added some sheet lead inside the tender for weight.
John C.