Gearbox issue

Hello, I'm renewing worn parts of my 1971 gearbox and among other things the mainshaft second gear teeth are pitted so I ordered part number 040418 from a shop. On a dry run build up I found the input and output shafts wouldn't turn freely. A process of elimination of new parts lead to finding the new 2nd gear as the problem. As far as I can gather it looks as if I've been supplied with a later gear denoted by the grooves cut into the dogs. Can anyone please confirm from my photo?