Found a photo to justify my locomotive :)

[doctorwayne]

....I was considering reconfiguring the running boards, but have since decided against it.
 

 

Yeah, on a metal boiler, that can be a bit of a job.  Where I wanted to put a stepped-up area to allow room for a water- or air-pump, I'd generally use a hacksaw to make the initial cuts, from their outboard edge, almost to the boiler.  I'd then grasp that segment with pliers, and simply break it off.  What was left was removed using a mill file.

To add the stepped-up portion, I'd drill fairly large holes (using small drill bits in a pin vise is miserable work on cast metal boilers) then use brass wire of the same diameter, forced into the holes, along with some ca or epoxy.  The portion of the wire that's left sticking out would have been worked-over with a file to flatten the top of the wire, and also to remove material from the bottom, so that it didn't look overly clunky. 

The raised step would be a piece of sheet brass, which could then be soldered onto the wires.

I later tried a slightly different method, still using a good-sized bit in a powered drill, but instead of using thick wire, I plugged the holes using suitably-sized styrene rod, secured with ca. 
The next step was to solder a couple pieces of phosphor-bronze wire (available from Tichy in a wide range of diameters) to the underside of the brass sheet.  This wire is considerably less-prone to bend than soft brass, so you can use a size that doesn't require thinning with files -.020" or .025" might be strong enough if you're careful when handling the locomotive.
For the final step, use the soldered-on wires to determine where you need to drill into the plastic plugs, in order to mount the new section of walkway - you can use a drill bit in a pin vise to drill the plastic (using an electric drill will make the hole too big if the drill's rpms can't be controlled).  When the wires are almost fully seated into the styrene plugs, apply a little ca to the still-visible portions of the wire, then push them home.

Here are a couple of photos of a Bowser PRR A-5 that I built for my good friend Charlie B., with a bump-up step added to match the set-up in a photo of the prototype...

   

   

While I cannot add photos directly to Big Blue from photobucket, I've discovered that by going to my photobucket albums, I can select a photo, then right click on it...a drop-down menu will appear, and near the bottom is an option to "view image info".
When I click on that, I get a page full of data, along with a partial view of the photo, and an option to "save as".  Clicking on that will place the photo into my desktop file for photos saved in the current year.  This is a lot easier than searching for the original photos, which are saved somewhere on a disc...some of them dating back 15 or 20 years ago.  The bonus is that the picture's file-size is automatically reduced to an amount useable for this Forum.

Wayne