Closer but no bananna...
You need to strip some of your html code out as this is not defining a page and requires not head tags, a point that barco pointed out. viewing your source this is want is contained currently in the header wrapper and of course the corresponding closing tags:
Code:
<!--bof-header logo and navigation display-->
<div id="headerWrapper">
<html>
<head>
<title>index</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body bgcolor=#8A876F leftmargin=0 topmargin=0 marginwidth=0 marginheight=0>
<table id="Table_01" width=1026 height=185 border=0 cellpadding=0 cellspacing=0 align="center">
but earlier in ths view Zen Cart already has this:
Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" dir="ltr" lang="en">
<head>
<title>HistoricalPreservation.org, The History Store</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-88
No need to repeat head, meta etc....just the relavant code to display the header and defined tables.
Now, I can see that this was for a previous site and there are some spacer tables that are not required also both left and right your full table ends up being 1026 px wide and you have the main wrapper defined as 950px an initial mis-match, then for other reason from the original there are spacer tables on the left and right and tables for the left, right and top brown border and these are handled now by some other border definition and also are not needed in your header.
There remain many many non-valid coding errors in this also.