This is a 1.5 ( so called due to the extra 'wriggle' engraving around the otherwise plain body) Hawaiian model with the cones and 't' piece replaced with a large slab of maple into which the pickup has been set.
National advertised a "send your instrument back and have it electrified" plan for single cone guitars,
(see the style 0 page for an example), so comparing the pick-ups used I believe this too was a factory fitted setup.
Note there is no tailpiece since the pu is also a bridge and tailpiece.
