Looking for blade information

I have a D4 6U that I need to rebuild the bottom (because on wear to the bolt holes) and replace the cutting edge and corners., on the back side of the blade, upper right is where there once may have been a tag but looks like it is long gone. I scraped the several layers of paint from it (between the rivets/pins that once held plate/tag and revealed a stamped number of 2A1 915 under where the plate once was.

Can anyone help with info with more information on the blade?

Thanks in advance

Here is the info on the blade...

Thanks for the help.

Rick