Removing a sticker from B unit

I would start with Dawn.  Take the shell off and let it soak for a little while in Dawn and warm water.  It won’t hurt the paint but it should loosen the sticker.

Have you tried a decal remover ?  You could just put it on the sticker itself so it wont bother the stripes.  Do a small test on the inside to make sure it does not alter the paint - it should't.  I have always had luck with it.   JP

In addition to the above good suggestions...

When trying to lift the sticker after soaking/wetting, try to carefully pull the sticker back on/across itself.  IOW, @ 180º.  Don't pull 90° to the stripe...that's increases the chance of pulling paint, too.

Another possibility would be to gently play some LOW heat on the sticker with a hair dryer.  In fact, you might want to lay a mask of aluminum foil on the body with a hole not much larger than the sticker when doing this.  LOW heat.  Not too close.  Check periodically to see if there's evidence it's softening the sticker's adhesive.

I'm betting, however, that Dawn or the decal remover (e.g., ELO by Testors) will do the trick.

BTW...let us all know how it goes.  We can all learn.

The appearance of the "4" looks like you've already tried to take it off. The above solutions sound plausible, but experience leads me to suggest that you leave it as is. Old stickers can be tricky. But then hey, maybe that's just me.

Soaked the shell in dawn and took a toothbrush to it and it came right off. Thank you so much everyone - such a great group to be part of, I really appreciate it!

Well, looks like the gamble paid off. So now there’s a blank rectangle right in the middle of the stripe where the number used to be. Just out of curiosity, are you going to leave it that way, or paint it the same shade as the stripe? 🤔