Unusual 2-Cent Blackjack Improper Revenue Use

Was going through some old acquisitions and stumbled across this one again. Having subsequently viewed a myriad of Blackjack improper uses, what springs to mind is just how unusual finding a multiple is.

You typically see these used as revenues on bank checks, drafts, receipts, or photos (CDVs), where they are almost universally found as single stamps.

I cannot recall another example of a multiple. It's a shame that it isn't still on the original document...

What do the inscriptions mean?

Likely the initials of the clerk recording the transaction and payment of the tax, along with the date April 8, 1864.