Scott, I don't know when the original 315 smokebox cleanout port was removed and welded shut, but it might not be totally out of line to consider putting it back on, although this would not match up with the intended 1940s era restoration goal. As I recall, the smokebox cinder drain port, which is also welded shut, aims straight down. I have no ides how that was configured. From the postings above, some engines had/have a curved drain that shoots the cinders out to the side rather than straight down. We might consider three options A. Issue high quality dust masks for those cleaning out the smoke box or B. Modify the Master Mechanic system ( I think there is probably little or no room for any changes) or C. Re-install the cleanout ports during the 1472 work. Just thinking.