Harold, I have that same locomotive and replaced that old 5V board with a PS32 board. That is a great locomotive with the monster Pittman motor. The latest PS3 version does not have that Pittman motor. The locomotive is well built and runs great. All I did to my locomotive was freshen up the smoke unit with modern wicking and new heaters.
Yes you can run a BCR if you wish. My choice would be a new MTH green battery. I do not want to get into a contest BCR V battery but that would be my choice. Old 5V boards are on overtime now and I get rid of them as time marches on. Many of my old 5V locomotives have been converted to PS2 3V boards. I have a large supply of those 3V boards thanks to George (GGG) Galyo. When George gets done with them, they are good to go.
Best of luck with your 5V locomotive. Again, the big motor is the hot set up for me. I am very happy with that locomotive and thankful to MTH for providing a work around fix for engines who have 5 volt boards.
If you go with the BCR, buy a NEW one. Do not use an old one that has been in use. Will an old BCR work, Maybe.