I spray paint all sorts of things. This is the kind of project that I would do without a lot of prep. Here's what I suggest, but I'm not an expert: Get a can of spray paint suitable for metal. Lightly sand the metal with sandpaper, sanding more where the rust is, wipe off the grit, and then spray according to the directions on the can. Here is a link that might be useful: Spray painting metal

I don't know about building codes in your area but here is something to consider. My sister-in-law has a pool with 3' of decking around the diving board, no matter how hard she trys, when her kids are playing they end up running through the grass, the grass turns into mud and it all ends up in the pool. When we did our pool this spring, we had them do a semi-circle around the diving board. We had the stamped concrete decking come out with a 6' radius from the bolt furthest from the pool. It has worked out great, when kids or adults are waiting they are not standing in mud & it is large enough for an adult to set up a chair if he is doing life guard duty.

I use Paint. In order to have more than one picture on a board, start a new file and make the white area quite large by dragging the edges. Save that as your main design file. Now, use the drop down box under the clipboard symbol. You'll see the option to "paste from" which, when chosen, will allow you to paste any other file on your computer by highlighting that file and clicking "open". Once you've pasted an element, you can move it around as long while it still has the dotted-line box around it. When you have placed the element where you want it on your board, click outside the element to fix it in place. Add more elements by chosing the "paste from" option again. You can also add text boxes to label elements, resize the elements, etc.

@SJ McCarthy I appreciate your response however... Stringers are actually on the outside of a stairwell that is open on one end. My stairs are sandwiched - that is not open on either end - between walls so the sides are called skirt boards. It isn’t a matter of semantics given location matters. I would encourage you to re-read my original post as you have made some very inaccurate assumptions, heavily deviated from the intent of my original post, exaggerated the work required, and have also not directly addressed my questions. Namely: 1. This project was cosmetic meaning there were no structural alterations. It seems you may be unfamiliar with how the lip of existing stair treads that remain in-place are adjusted to receive hardwood treads and risers right atop to preserve the minimal costmetic nature of the “renovation“. Regardless, references to code are therefore entirely irrelevant. This is a quality/ craftsmanship issue from an aesthetic perspective! 2. I get that the average homeowner may not be the most informed, although NOT everyone is so “green” to pay upfront giving a contractor no incentive to do the job in which they were hired to complete. 3. Similarly, one shouldn’t assume that the ‘big boys’ always perform as they are contracted. Unfortunately, in my case, Class A contractors who are insured and bonded with decades of experience aren’t immune to performing subpar work nor subcontracting out to those who perform subpar work. Thankfully, I had hours of video footage to substantiate what was/was not done! With all of this said, I am seeking insight into how this - filling shallow holes/depressions should be flushed out with skirt boards - NOT who should be hired to do the work. If you cannot answer, that is fine although I would appreciate responses to my actual questions. Note: 1. It is NOT necessary to replace skirt boards therefore all of the extra mentioned is beyond overkill, and, quite frankly, off topic. 2. This inquiry is limited to flushing out depressions and filling in boundaries between wood plugs and skirt boards.