Seca fork slider oil passage holes welded up.

Hi guys. I have just stripped my forks and found that both inner sliders / stanchions have one of the lower oil holes welded up.
I am not sure what these holes are for but I'm guessing rebound damping?
I am rebuilding the forks and anti dive units.
Has anyone ever come across this beforehand? If it's the rebound then it will just slow this?
I have only had a quick ride around the block so didn't really get a feel for the fork setup.
I am happy to either leave or re drill the holes for the best results.

Thanks