It is not SL 1859 4d SG 4 because the stamp shown here is perforated.
It is most likely SL 1867 4d SG 65b.
Of course !
I was responding to a post without an image. (Note the time stamps on the posts)
We have to do that here, images are not always posted first
A tough gig, assisting without full particulars.
but, we try and help as best we can.