Marty, this is a project to which I gave much thought. I concluded that the PS3 S-gauge board, which apparently is only used in the O-gauge 44-ton GE, will fit in place of the existing board. I reached this conclusion my measuring the boards on each of these locos, both of which I have. I eventually decided not to proceed with the project, because I didn't want to spend the dollars. Not only the price of the board, but also having to replace the couplers. Plus the fact that the docksider, with its grooved wheels, is noisy and really has little pulling power to tackle my grades.
BUT, please make your own conclusions about whether the PS3 board will fit. I could have erred.
I have heard that the HO PS3 boards have a 1-amp capacity. My running tests showed that under certain conditions, the Docksider can pull more than one amp.