Oh darn! Be careful! Now don't go enthusiastically sanding down that blade.
I mean, I don't want to come over as condescending and I do not know your skills, but there are about 2 ways to do a job on blades like this. That is why I have this love - hate relationship with engraved blades, even with the blue and gild all gone, as seems to be the case here.
If you do not mind, I'd like to make a proposal of what I would do.
1. Get a roll of toiletpaper and a can of oil. WD 40 is excellent for cleaning.
Clean the blade really well.
2. Get super fine steel wool and spray some oil on it. Now softly go over the engraved area, always lengthwise up to about 2" from the last engraving. Have an eye out for any fading of the engravings. Normally they are quite deep, so there shouldn't be any problems, but as we do not know how many people have been cleaning this blade and I cannot see from here, just be careful.
At some point you will see the engraved area brighten up a bit. It will not be highly polished, but just brighter.
3. Clean the blade and now go over the engraved area with a soft cloth and some Mothers to finish.
4. Clean the blade again, first with oil to remove the Mothers or any other chrome polish compound you have used and lastly with a soft cloth and some acetone to remove all traces of dirt and fat that may remain.
5. Get a roll of painters tape, the paper stuff of about 2 cm wide.
About 1" past the last engraving is where the old blue stopped in a nice straight line.
Tape this off. That is to say: glue the tape inside the 1" area so one side of the tape marks the border with the rest of the blade. The 1" area is now protected and a nice straight line will develop when you do the rest of the blade. I hope I made myself clear here.
6. With the engraved, formerly blued, area secured you can go over the rest of the blade in any way you want. If this sabre was mine I'd just take a bit of a brown 3M sanding mat and some oil, always sanding in the length of the blade in short 10 cm strokes, followed with a bit of a grey 3M sanding mat, coarse steel wool, middle grid steel wool and super fine steel wool, the soft 0000 sort. Work carefully up against the paper tape as close as you can without bumping into it. You want to have that nice straight line. Clean with oil and a piece of soft cloth between the stages.
As I do not like the effect of Mothers polish compound has on steel, I stop after the super fine steel wool, but it is up to you if you want to finish with Mothers.
7. When done, remove the tape and clean the blade with acetone.
If you like what you see you can stop here, but if you want to enhance the contrast between the engraved part and the rest of the blade, you take the tape again and glue a piece right up against the line but now on the polished blade side. With a piece of 0000 steel wool now go over the engraved part again, but now over the width of the blade.
8. Clean up and you can protect the blade with oil, but I am a fan of Ren Wax as it does what it says on the tin. It is quite expensive but lasts a long time. I have done I think 25 blades with my little tub and there is still enough left for another 10.
The blade now should look a bit like this, but I used the grey or brown mat ( I cannot remember) to go over the width of the engraved part:
The engravings on my blade look much more pronounced in reality. The camera somehow did not catch it. And in retrospect, I made the engraved part too dull. I will have to go over it, in the width, with super fine 0000 again to polish it up a bit.
This all may look like a daunting project, but in reality you can do this over a weekend.
I hope, whatever you decide to do, you'll have the blade you want.
That is what this is all about in the end.
Cheers.