Nice work, working with a blade that large is pretty difficult.
You asked for suggestions so here it goes...... The marks left in the blade look like imbedded scale. The scale problem can be easily prevented next time by using a wet anvil technique.
Here's what I do....
I heat the blade, wipe my anvil with the back of a gloved hand and dip my hammer in a pail of water. I then place the hammer on the anvil and paint on the water. This covers the working surface with a thin coating of water. When the knife comes out of the heat, on the first hit, all the cr@p is blown off the blade. I wipe again and go to forging. I'm having very few scale problems now since I changed over to this method. The technique comes from Japan, making Samurai swords. It's of course not the only way to prevent scale but it works good for me.
Keep up the good work.
Regards
Loyd Shindelbower
Loveland Colorado