This is the 1881 1d Inland Revenue stamp with orb watermark.
I was ready to add this to the revenue/fiscals stockbook but I noted the cancel was (I think) a postal-type oval registry cancel for Gresham House (EC2, London). That is indeed in blue; first time for me to see an oval registry cancel struck in blue.
So is this postal usage or fiscal? I know high values were used to pay for both charges and 1d on a registered cover might be from that kind of usage. And does a blue oval registry cancel have some meaning?