+1
If you haven't used tape, the only possible explanation is that the razor was previously honed with several layers of tape. It's a common practice on wedges. Because of that, the bevel is much obtuser than normal. Your honing without tape is slowly replacing it with a new bevel with normal angle. You can actually see that your DMT scratches are not running all the way trough. It comes more apparent after the DMT and even more after polishing on the Coticule with water.
You must hone on the DMT till the new bevel runs all the way to the apex of the blade. That can take many 100's of laps. Check out the Magic Marker Test (MMT), great to see if the new bevel is completely developed yet, or more work is needed.
This is also a perfect example of a razor that would benefit the downstroking technique. Run the edge over the bottom of a glas jar once, so it dulls just enough to duck all sharpness tests such as the TNT and the shave arm hair test. Now you can hone on the DMT, till the entire edge starts to pass those tests again. That way, you can be sure of a complete bevel after the DMT.
You can read more about bevel-setting in this wiki article: Bevel-setting in theory and practice - Straight Razor Place Wiki
Don't you dare giving up on that razor. I'm taking this personal.:D
Bart.