I left the original Bachmann circuit board in place and wired it to the Blunami BLU-4408 decoder. The BLU-4408, battery and original circuit board in in the tender. Both the front and rear lights, cab light and flicker box are all working. The installation took me a number of weeks research, re-researching, reaching out to others, browsing a number of websites but in the end was much simpler and easier than I originally thought. I learned a lot in this process both regarding the wiring and the mechanical parts of this locomotive. It’s very satisfying that all is working as expected. Fun project! 
