Will take pics in the spring.  The floor is metal, a light brown pattern if I recall, with provision made to slide in the extra seat.  It is covered by a brown carpet.

From: JordanVw@aol.com
Date: Mon, 9 Feb 2015 14:18:04 -0500
Subject: Re: Eberspacher BA6 gas heaters on canadian waterboxer vanagons...
To: jpalmer@mymts.net
CC: vanagon@GERRY.VANAGON.COM

In a message dated 2/9/2015 2:03:23 P.M. Eastern Standard Time, 
jpalmer@mymts.net writes:
Walk 
  through area is carpeted. Separate carpet behind the vent after the elevation 
  change (in the "living area"). 

 
sounds like the walkthru floor sheetmetal is different on the vanagons 
which had gas heaters installed, sounds like they used aircooled vanagon 
walkthru sheetmetal there from the factory..  very interesting.. would love 
to see a pic  when you get van out of storage.