I’m not sure where to find the rule requiring headlights to be on, but I’m pretty sure that it is mandated by the FRA.
As far as side rods go, the FRA has no written prohibition against painting them, and various roads do or did paint some or all of their rods. For example, Baldwin Standard Practice called for rods to be polished on class I locomotives and painted on engines built for short lines. EBT’s engines have never not had their rods painted. Santa Fe commonly painted their side rods. We more often than not paint the flutes of our main rods for cosmetic effect, and clear coat all of the rest.
I recall folks at the C&TS saying that their inspector wouldn’t even allow clear coat on their rods, but I suspect that may have been a hang up for that particular inspector. We had one once that would write us up for having oil on the faces of the tender wheels because it might hide a crack. He had no problem with oil being on the face of every wheel on our passenger cars, but there better not be a drop on the tender wheels.
For your reading pleasure:
FRA Part 230
Quote
§230.96 Main, side, and valve motion rods.
(a) General. Main, side or valve motion rods developing cracks or becoming otherwise defective shall be removed from service immediately and repaired or renewed.
(b) Repairs. Repairs, and welding of main, side or valve motion rods shall be made in accordance with an accepted national standard. The steam locomotive owner and/or operator shall submit a written request for approval to the FRA Regional Administrator prior to welding defective main rods, side rods, and valve gear components.
(c) Bearings and bushings. Bearings and bushings shall so fit the rods as to be in a safe and suitable condition for service, and means shall be provided to prevent bushings from turning in the rod. Straps shall fit and be securely bolted to rods. Floating bushings need not be provided with means to prevent bushings from turning.
(d) Side motion of rods. The total amount of side motion of each rod on its crank pin shall not exceed 1⁄4 inch.
(e) Oil and grease cups. Oil and grease cups shall be securely attached to rods, and grease cup plugs shall be equipped with a suitable fastening that will prevent them from being ejected.
(f) Main rod bearings. The bore of main rod bearings shall not exceed pin diameters more than 3⁄32 inch at front or back end. The total lost motion at both ends shall not exceed 5⁄32 inch.
(g) Side rod bearings. The bore of side rod bearings shall not exceed pin diameters more than 5⁄32 inch on main pin nor more than 3⁄16 inch on other pins.
