It occurred to me as I used my last spare smoke PCB, that since I do a lot of smoke unit repairs and upgrades specifically for steam, that maybe it made sense to make my own PCB. Many times for upgrades I don't use the power source, so it would be nice to simply remove those components. Wait: I can simply leave them off. Other little things, I made the intake hole 1/4" since I always drill that out anyway. I also removed the jumper between the two pins of the 3-pin connector. This is useful so you can power the 5V supply independent of the smoke resistor. This also allows you to use the 5V supply independently, this eliminates the need for me to supply a separate supply for some tasks. I also isolated the smoke resistor totally from the ground, there's no real reason to have all that extra copper doing basically nothing.
So here it is, the replacement smoke PCB for standard Lionel 610-8057-200 rectangular smoke units.
I put in an order at JLCPCB for some of these, so it'll be a few weeks before I get to test one out. I don't anticipate any issues, I insured the holes liked up perfectly with the stock PCB, which would be the major issue I can foresee.
Boards are in, look great, here's the Gerber Files for anyone to duplicate them.