Glad to see you’re having fun Ron!!!
I don’t even think about the value of an engine when I do my conversions, it’s what I want that counts.
All my steamers except one have the on/off switch and charging jack under a fake, foam rubber coal load that is easily removed. The one steamer happens to be the biggest one of all, my brass Willams N&W 611, not sure why I put the on/off switch underneath but it’s time I moved it to the coal bunker like the rest.