I checked the hex for a "rough stone knife" and the byte array is the same. If you have trouble finding it, look at where the byte array starts and ends.
From the excel sheets shared previously, the default "stone knife" value is:
01 00 00 00 00 00 00 00 00 53 74 6F 6E 65 20 6B 6E 69 66 65 00 73 74 72 69 6E 67 2A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 4B 4E 49 46 45 00 61 74 6F 6E 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 77 70 2D 73 74 6E 6B 6E 69 66 65 00 00 00 46 00 00 00 00 00 C8 01 01 00 00 00 00 00 00 00 00 00 00 00 00 00 53 89 29 3F 53 89 29 3F 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00
"Normal" stone knife is:
01 00 00 00 00 00 00 00 00 53 74 6F 6E 65 20 6B 6E 69 66 65 00 73 74 72 69 6E 67 2A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 4B 4E 49 46 45 00 61 74 6F 6E 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 77 70 2D 73 74 6E 6B 6E 69 66 65 00 00 00 46 00 00 00 00 00 C8 01 01 00 00 00 00 00 00 00 00 00 00 00 00 00 53 89 29 3F 53 89 29 3F 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 83 00 01 00 00 00 00
"Rough" stone knife is:
01 00 00 00 00 00 00 00 00 53 74 6F 6E 65 20 6B 6E 69 66 65 00 73 74 72 69 6E 67 2A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 4B 4E 49 46 45 00 61 74 6F 6E 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 77 70 2D 73 74 6E 6B 6E 69 66 65 00 00 00 46 00 00 00 00 00 C8 01 01 00 00 00 00 00 00 00 00 00 00 00 00 00 53 89 29 3F 53 89 29 3F 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 82 00 01 00 00 00 00
To be sure, I am testing this on a different PC. But keep in mind this is a Steam version. Hope it helps.
If it's still confusing, I found a rough stone knife I crafted using this array byte search in the Cheat Engine's memory view (press Ctrl+F, then click on array byte, then Ctrl+V the array byte for the stone knife) - see the attached screenshot. Then I changed the value 82 to 83 (at the end) and had it changed its quality. Now by replacing the entire line from 01 to 01 00 00 00 00 with something else, e.g. mastercrafted splitting axe, I can change the item.
It's very rudimentary and it's a hit and miss approach but it still works on 3.86.1