Scottnon, sad to say, not many people visit this forum--but if you go to the Model Railroad forums and post your question, you may receive several answers to your question--and then be able to find the ladder that you need to safely work on your layout.
Yes, take time to read thru ALL the forums.
You want a top side creeper from Micro Mark. Google topside creeper micro mark. Used also for working on car or pickup truck engines.
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.