AlexM, I feel your concern. I too had to repair my BB after abusing its smoke units by either over-filling or starving them; ruined the smoke units and broke the RCMC as part of that; Mike R. did the initial repair of all that and provided a good base for the next repair.
The main smoke unit failed some time later and I did that repair myself - sloooow and meticulous with loads of help from the forum: https://ogrforum.ogaugerr.com/...opped-working?page=1