Raised Stringers From Factory??

[Surfnski]

Hello gents,

I recently demoed the original floor on a 1974 twin I/O Scepter and discovered that the stringers were capped with a layer of 3/4” plywood covered by CSM. Has anyone encountered this before? From most of the rebuilds I’ve seen it appears that the deck is bonded directly to the glass tops of the stringers. Deck appears to be original so it seems that this was done at the factory. Possibly in an attempt to make the stern heavy twin I/O bail better? Has anyone seen this before??