Need REST access to information available in XML dump of website

We have a WordPress eXtended RSS file generated by WordPress as an export of your site. It list all kind of things that I cannot find using REST queries. Most notable is an item which says, in part,

        <item&gt
            <title><![CDATA[MKT Products [NEW]]]></title>
            <wp:post_id>14146</wp:post_id>
            <wp:post_type><![CDATA[dtwpb_product_tpl]]></wp:post_type>
            <wp:postmeta>

after which come a host…