There's at least one reputable vendor on Etsy who makes decals for Typewriters. I bet you could get new ones made up for you. I know they do custom orders. I plan on getting some new decals myself once I get around to it.

Hmm. Good question. To which, I do not have the answer.

Seijun wrote:

I am still working on cleaning this little machine. Does anyone know what the metal trim is made from that borders the ribbon cover? In some pictures online it appears to be chrome (like here), but on mine it is a flat yellowish-grey. I am wondering if it needs to be polished or if this is the natural color on some machines?

tl:dr; read just the last paragraph

Nothing structural is "made from" chrome. Chrome is a protective metal that is electroplated onto the piece in order to look shiny and prevent rust. The piece itself is made of a sturdier, cheaper metal than chrome, usually steel. Test the strip on your typewriter with a magnet---it's probably steel. Not likely to be plastic on a machine as old as yours, though that is common on newer ones---'60s, '70s, onward.

Older machines had nickel plating instead of chrome plating. The switchover happened generally during the 1920s, at different times for different products and companies. Though both are silvery and shiny, there are real differences. Nickel looks like it has a soft yellowish tone; chrome looks more bluish. Side by side it's easy to tell the difference and you can develop a eye for it so you can recognize each one in isolation. Nickel does tarnish and chrome does not. Both can develop microscopic pinholes that let the underlying metal rust and discolor the finish. Your "flat, yellowish-grey" might be tobacco stains over chrome.

But you really just want to know how to clean it, right? Soap and water first and be sure to dry it afterward. The commercial product "Scrubbing Bubbles" works very well for tough grime even on crinkle paint but keep it away from decals. A very gentle polish like Simichrome, applied gently, works well for me. Some people like to rub the part with aluminum foil but I haven't tried that. Be aware that nickel is very much softer than chrome and it's kinda easy to rub right through the plating. Chrome is much harder and can handle gentle rubbing with steel wool. If you do rub through, you will probably first hit copper, which was often plated on before the top layer, so it looks reddish, not like steel. That's you warning. Whatever rubbing you do, stay away from the adjacent paint, as paint is very much softer even than nickel. HTH and good luck.

.

Soap and water has so far not had any effect on the strip. I tested with a magnet and it is steel underneath. The surface color is a dark, slightly yellow-tinted, matte grey, dotted all over with faint black spots and swirls. Looks like on this machine (mine also came with a horrific brown-green case instead of the usual black).
I polished a corner for a while with simichrome and it didn't have any effect other than to make the surface a little smoother to the touch. No color change. 

Seijun wrote:

Soap and water has so far not had any effect on the strip. I tested with a magnet and it is steel underneath. The surface color is a dark, slightly yellow-tinted, matte grey, dotted all over with faint black spots and swirls. Looks like on this machine (mine also came with a horrific brown-green case instead of the usual black).
I polished a corner for a while with simichrome and it didn't have any effect other than to make the surface a little smoother to the touch. No color change. 

Well, that's certainly very different from the reflective shiny surface in your original example post. I don't recognize this finish and Uwe is certainly right about the budget aspect and production variations over time. I would not mess with this decorative strip for now and would take the time to learn better about the material. You did the right thing to come to this forum as your research. Let this play out, keep asking, someone will eventually have a valid bit of experience with it. For now, figure that this is how Royal expected it to look---it's different and interesting.