That is a beautiful block! Yes, this is from Kilauea, Hawaii and the bottom should be "H.ISLS."
Also, the killer portion of the duplex cancel will be "HAWAII" since Kilauea is on the Big Island of Hawaii.
Here is a similar cancel from my collection from Lihue, Hawaiian Islands, with a "KAUAI" duplex killer. See this link:http://goscf.com/t/65669
Hope this helps you,