What do you want done with it?

The so called NATO didn't come out until the 1970s, so it's unlikely that type of strap was used on this watch originally, though it may have had a simple woven under-the-case nylon strap prior to that.

Hi 17653 is the case serial #, not the reference number.

I have seen these hands before with luminous material painted directly on them, so they're not necessarily 'incorrect' though someone appears to have just painted them white.

The case has an odd SECOND serial #, did you see that?

The band won't add any value. Is it gold or 'gold filled'?

Yes correct the dial is more in block letters, on the German delivery model, my error. This one is 'civilian' all the way.

It's under the balance wheel in the photo (the largest moving part) ending in "/A", I can't make it out.

So it's something like 4XX/A where I can't make out the X.

That would date the watch to 1944-1945. I can't make out the movement caliber from the photos, but its one of the 400 series, like 478, 450, etc.

Though it is the correct back, I think the back is from another watch or the movement came from another watch. Replate is less than an original in good condition, better than a trashed case. These chrome plated tops usually didn't last too long before showing wear.

A picture of the movement with its serial # for any further info.